build-report

name	build-report
description	Build polished analytical reports for executive, product, business, or technical audiences. Use when the task needs a durable answer-first narrative with evidence-backed findings, visuals or tables, caveats, and source context.

Related Skills

Use the focused analysis skill before building the report when the report depends on market sizing, metric diagnostics, KPI reporting, product/business analysis, data-quality checks, or validation.

Report Building

Use this skill when the user needs a durable analytical report rather than a dashboard, notebook-only dump, or transient chat summary. The report owns the reader-facing narrative, audience shape, evidence placement, visual/table placement, caveats, source metadata, and handoff. The underlying analysis should still come from the appropriate analysis, notebook, data quality, diagnostics, KPI, or product-analysis workflow.

If this skill is selected directly or included by a report-mode workflow, the run is incomplete until the selected report surface exists or a concrete blocker is recorded. Do not finalize with chat-only prose, an inline widget, a local URL, or an ad hoc artifact that skips the report shape. Treat inline summaries and notebook outputs as progress evidence, not as substitutes for the report. Once this skill is selected, reserve charts, tables, and previews for the selected report surface. A user can explicitly waive report creation by requesting an inline, chat-only, brief/no-artifact answer, asking for no report/file/artifact, or selecting another primary artifact. Do not infer a waiver from the absence of the word "report" or from a direct diagnostic, recommendation, sizing, or readout question.

Skill Configuration

Choose exactly one report delivery mode for each run:

• Codex desktop: use mcp-app by default.
• Positively identified ChatGPT web Work Mode: use html; MCP app report rendering does not work on that surface. MCP servers and other callable tools remain valid evidence sources.
• Work Mode signal with unknown or non-desktop surface: use html; do not treat an unknown surface classification as permission to render an MCP app report. Only a positive surface = codex_desktop signal may take the Codex desktop MCP default.
• Any other runtime where MCP app report rendering is unavailable: use html.
• Unknown or unclassified runtime: default to portable html rather than omitting the report.

On Codex desktop, use html only when the user explicitly asks for HTML, offline portability, a file-based artifact, or no MCP rendering; a requested downstream conversion requires HTML; or an MCP app report was actually attempted and failed because the capability was unavailable or a documented renderer limit was exceeded.

If the selected MCP app report cannot be rendered after one targeted correction, fall back to html in the same run unless the user explicitly declined HTML. A renderer failure changes the delivery mode; it does not waive the report. If neither surface can be created, record the concrete blocker and the attempted surfaces before finalizing.

If an MCP app report was already rendered and the current context later identifies Work Mode without a positive Codex desktop surface, treat the MCP artifact as the wrong delivery mode. Rebuild the report as self-contained HTML before final handoff instead of explaining that the MCP artifact is acceptable.

Select exactly one delivery mode per run. Do not build an MCP app report and a static report.html as parallel outputs unless the user explicitly asks for a second delivery mode as a separate follow-up. For every selected HTML report path, including Codex desktop explicit HTML, ChatGPT web Work Mode, and HTML created for PDF, Google Docs, or Google Slides conversion, use the precompiled Recharts-in-HTML path in recharts-html.md, with a readable same-data static fallback in the delivered HTML.

Workflow

1. Define the reporting job.

   State the user question, decision or action the report should support, primary audience, scope, time frame, comparison baseline, success criteria, and what would make the report decision-useful. Choose exactly one audience:

   • product stakeholders: default for product, business, leadership, strategy, diagnostics, KPI readouts, and general stakeholder reports.
   • technical: only when the user asks for a technical or methods-first report, or when the report's main value is methodology such as metric definitions, measurement design, statistics, modeling, experimentation, or validation.

   If the work is unusually methodology-heavy but the user did not ask for a technical audience, ask before switching.

2. Read the matching audience specification.

   Read exactly one matching audience specification before gathering evidence, shaping the report spine, or drafting the report surface:

   • executive-report.md for product stakeholders
   • technical-report.md for technical

   Treat the selected audience specification as a report-quality contract, not as a replacement for the workflow below. Capture its Required Structure entries in the report plan or supporting source notes, and stop with a blocker if the matching specification cannot be read.

3. Gather and bound the evidence.

   Inventory the source data, metric definitions, denominators, assumptions, requested cuts, caveats, notebooks, SQL, scripts, query permalinks, source documents, and reviewed datasets needed to support the report. Resolve ambiguities before drafting claims. If a requested metric or cut cannot be supported, record why and state what evidence would be needed to add it. Preserve process notes, source inventory, and reproducibility notes in source metadata, source notes, or supporting artifacts, not in the visible report body.

   When this skill is selected directly and the user explicitly asks to "use sample data" or create a report "using the sample data" without naming or attaching a different sample, treat that wording as selection of the bundled synthetic demo. Resolve demo-product-growth.csv relative to this skill, analyze those rows, label them synthetic, and do not search the workspace for a substitute or invent replacement data.

4. Distill the report spine.

   Before choosing a delivery surface, write or mentally verify a compact answer-first report spine with these entries:

   • question
   • decision-useful answer

Lead with the selected report artifact result or blocker. Then list only the relevant MCP app artifact or HTML report path, plus supporting source, SQL, code, notebook, and chart artifacts. In HTML mode, the actual interactive report.html file is the primary deliverable. A rendered PNG or screenshot may be included only as a labeled non-interactive QA preview; never use image.png, a screenshot, or another flattened image as the only report handoff. If the host cannot render HTML inline, attach or link the .html file instead of flattening it. Self-audit the report against the quality bar before handoff. If HTML sharing or conversion is needed and safe, resolve the presentation surface; otherwise record why sharing was unsafe, unavailable, or explicitly waived. Do not substitute a chat summary for the report.

Report Standards

PDF Export Specifications

When the user asks to export a Data Analytics report, dashboard, or inline chart surface to PDF, use report-to-pdf. That sub-skill owns PDF conversion mechanics so this root workflow stays delivery-mode neutral.

MCP App Report Specifications

Read mcp-app-report.md when the selected report surface is an MCP app report. That file owns MCP app report mechanics so this root workflow stays delivery-mode neutral.

HTML Report Specifications

• Use HTML mode only under the delivery rule in Skill Configuration; on Codex desktop, do not choose it before an MCP attempt unless the user or downstream conversion explicitly requires HTML.
• For every HTML report path, read recharts-html.md, start from ../../assets/html-report-shell.html, and preserve or adapt its report data-contract-section attributes to the selected audience specification. Use its packaged Recharts runtime for live charts and keep same-data static SVG/table fallbacks directly in the HTML.
• Preserve the shell's automatic system appearance support in every HTML report: keep <meta name="color-scheme" content="light dark">, semantic color tokens, and the @media (prefers-color-scheme: dark) token overrides. Verify report content, charts, fallbacks, source tooltips, and focus states in both light and dark system modes; do not replace this behavior with a manual-only theme toggle.
• Keep the HTML reading path report-like: answer first, visible segment titles, evidence and interpretation together, caveats where they matter, and source metadata preserved without appending a visible sources, notes, or reproducibility appendix unless the user explicitly asks for it.
• Give every source-backed quantitative value in an HTML report a directly associated source tooltip. This includes headline and KPI values, inline numeric claims, table values, and other displayed numbers derived from retrieved data. The tooltip must identify Source: <source system, connector, or artifact> and, for structured data, Table: <fully qualified table or view>. For a value derived from joins or multiple inputs, list every material contributing source and table. For non-tabular evidence, replace Table with the precise Dataset, File, or Document name. Never invent provenance; mark an unavailable table or source explicitly and preserve the gap in source notes.
• Implement HTML source tooltips as real hover and keyboard-focus affordances using the shell's source-tooltip pattern, not only a native title attribute. Keep the number readable without interaction and the tooltip text concise. Associate each tooltip with the number it supports; a shared tooltip is acceptable only when it unambiguously covers every number in the containing group and all share identical provenance.
• Use the same shared source-tooltip-content style for narrative values, KPI and metric-card values, table values, and chart figures. Do not create card-, narrative-, table-, or chart-specific tooltip variants. Foreground, background, typography, padding, radius, and shadow must match, and tooltip text must explicitly use the shared foreground color instead of inheriting a muted or emphasized color from its surrounding value.

Narrative

• Every report must have a short plain-English reader-facing title. For HTML reports, use the same title in the document title and visible page header. For MCP app reports, follow mcp-app-report.md.
• Do not duplicate the title or executive summary in an unlabeled subtitle, lede, scope line, or second summary block.
• Treat the report title and executive summary as separate visible elements. The report title is the artifact-level name; it does not satisfy the executive-summary section role. For stakeholder reports, render a visible Executive Summary section heading immediately after the title before the summary content.
• Open stakeholder reports with an executive summary that answers the user's question directly. Default to 2-4 bullets or short mini-paragraphs with bold topic sentences.
• Open technical reports with a technical summary that states the main result, then provide definitions, methods, uncertainty, and limitations needed to trust it.
• Start major report segments with the takeaway, not setup prose. Use headings that carry the insight rather than copying generic labels.
• Include visible titles for every major report segment in every delivery mode. Titles are part of the reader-facing report contract, not just private metadata. In HTML reports, render titles as heading elements inside sections. For MCP app reports, follow mcp-app-report.md. Use story-specific titles such as "API ARR is pulling ahead of plan" rather than generic labels when the evidence supports it.
• Keep an obvious top-to-bottom report reading path. Do not turn a report into a dashboard grid unless the user asked for a dashboard. Use a single-column document flow by default; half-width visual blocks are acceptable only when labels, series, and interpretation remain readable in the selected surface.
• Use report markdown blocks for narrative insights and interpretation. Give each independently laid out or editable major report segment its own markdown block; do not place multiple peer ## section headings in one markdown body. Use ### headings only for subordinate content that should remain in the same card. Keep chart/table headers neutral, and put takeaways in adjacent narrative blocks rather than hiding the argument inside visual metadata. Markdown blocks are the primary place for the story.
• Reports should be substantial enough to stand on their own. Do not deliver a report that is mostly a chart/table bundle with a short summary. The reader should be able to understand the answer, evidence, interpretation, caveats, and recommended next step from the narrative itself.
• Use flexible section names and story-specific ordering, but make sure the report still does the core jobs: answer the user's question directly; explain the metric, cohort, denominator, time window, and comparison basis when they affect interpretation; pair each important number or visual with plain-English interpretation; explain why the finding matters for the decision; state what remains uncertain or could change the conclusion; and include a practical next step when the evidence supports one.

Evidence And Sources

• Base every major claim on saved data, code, query results, notebook outputs, source documents, or rendered charts created or inspected during the task.
• Tie important numbers, charts, and recommendations to readable source metadata near the relevant paragraph or visual when the selected surface supports it.
• Keep raw paths, notebook locations, temp directories, request IDs, and implementation-facing audit details in source metadata, source notes, or supporting artifacts unless needed for trust. In HTML reports, expose source-system and table names in the source tooltips required by HTML Report Specifications; keep them out of the always-visible narrative unless needed for trust.
• Keep source SQL in source metadata, source modals, linked query artifacts, or supporting notes. Do not paste source SQL into the visible report body or final chat handoff unless the user explicitly asks to see, write, review, debug, or receive SQL or query methodology.
• Do not add a visible bottom sources, notes, or reproducibility section unless the user explicitly asks for that methods layer.
• Preserve source datasets, query or transformation artifacts, rendering code, output folders, assumptions, omitted metrics, and chart QA notes in source metadata, source notes, or supporting artifacts even when they are not visible in the report body.
• Surface enough evidence affordance for audit without creating a heavy visible claim graph. Prefer block-level source references when the surface supports them.

Visuals And Tables

• Report visual headers should be neutral: chart/table name plus a short description only when needed for metric, denominator, cohort, filter, or time window. Put narrative insights and caveats in adjacent markdown blocks.
• Every report visualization must have an adjacent explanatory paragraph immediately before or after it in the reading flow. The paragraph should state the takeaway, how to read the visual, and the implication or caveat needed to interpret it; chart titles, subtitles, captions, metric cards, or table headers do not satisfy this requirement by themselves.
• Chart and table subtitles should add a reader-facing insight or interpretive context that the title does not already cover. Prefer direction, magnitude, inflection, rank, comparison basis, scope, time period, unit of measurement, filters/exclusions, denominator, cohort, sample size, or basis of comparison, such as Growth accelerated after mid-April and ended at a period high or FY2021-FY2024, values in millions of USD. Keep descriptions and subtitles hidden by default unless showDescription or an equivalent flag is needed to clarify the reading path.
• Prefer human-readable dates in visible markdown, chart titles/subtitles, captions, table labels, and generated-date chrome. Keep ISO timestamps in query bindings, source metadata, and other machine-readable fields.
• Do not use source table names, raw query ids, dashboard slugs, notebook paths, SQL intent, metric definitions, or implementation labels as chart/table subtitles. Put those details in source metadata, source notes, or supporting artifacts unless the source identity is itself essential for reader trust. For HTML reports, source-system and table names must also appear in the related number or chart source tooltips, where they remain available without cluttering the subtitle.
• Before rendering report tables, check every table subtitle against the table title and visible columns. If it does not clarify what rows are in scope, what period is covered, how values are measured, which filters apply, or what comparison is being made, rewrite it or omit it rather than falling back to the source name.
• Do not shrink visuals into unreadable sidecards. Use full-width blocks for dense charts, long labels, or HTML chart fallbacks that need more room.
• Put report charts on their own readable row or block in the reading flow unless a half-width layout has been checked in final context and remains legible. Do not use narrow right-rail chart cards for report evidence.
• Report trend charts need enough observed data to make the shape worth reading. When a report chart would show only a few anchor periods, route back through $visualize-data to request a finer grain, longer lookback, or meaningful segment breakdown before rendering. If the source cannot support that without misleading the reader, replace the trend with a KPI strip, grouped period bars, table, or concise narrative comparison and record the omitted richer trend in source notes or supporting artifacts.

Metrics And Language

• Describe metrics in plain English before exposing implementation details.
• Clarify definitions, cohorts, denominators, filters, and comparison baselines before relying on a metric in the report.
• Choose the most interpretable audience-facing grain: user, account, workspace, task, turn, session, request, revenue, endpoint, customer, org, or another business-facing unit.
• Put raw numbers in context: percent of an active base, percent of the previous funnel step, percent of total change, comparison to baseline, target, peer segment, or historical range.
• Use shorthand large numbers in narrative text, chart labels, and summaries, such as 899k, 10.9k, or 1.2M. Reserve exact comma-separated values for audit tables, SQL outputs, appendices, or cases where precision changes the interpretation.
• Keep implementation-facing event names, field names, table names, and exact predicates out of the main narrative unless they are essential for trust. Put them in caveats, source metadata, or short parentheticals.
• Polish the final language for the selected audience: concise, answer-first, free of process notes, and no deeper on methodology than the audience needs to trust the result.

Quality Bar

Before final handoff, confirm:

• if any required item below fails, fix the report or record the blocking gap explicitly before finalizing
• exactly one delivery mode and exactly one audience specification were used, unless the user explicitly asked for a hybrid or second delivery mode
• the selected audience specification's Required Structure maps to visible report sections, with any merge, rename, reorder, or omission recorded in source notes or supporting artifacts
• the report spine, report depth gate, selected delivery-mode specification, and rendered report were all checked
• the rendered report answers the user directly, has visible reader-facing segment titles, and pairs each major claim with evidence, interpretation, caveats where needed, and a decision-useful implication
• definitions, denominators, baselines, requested metrics, and caveats are clarified before final claims are treated as decision-ready; omitted metrics have a reason and needed follow-up
• methodology depth fits the selected audience, and omitted requested metrics are explained with the reason and needed follow-up
• visuals and tables were routed through $visualize-data, inspected in the selected surface, and remain readable with useful subtitles, adjacent explanatory paragraphs for every visualization, source metadata, and supporting notes
• every source-backed quantitative value in an HTML report has a working hover and keyboard-focus source tooltip, and every static chart figure has an equivalent tooltip, with exact source-system and table, view, dataset, file, or document provenance
• sources and reproducibility notes, chart maps, and omission reasons are preserved in metadata, source notes, or supporting artifacts without cluttering the visible report
• the final handoff lists the selected report artifact plus relevant supporting evidence, not a chat-summary substitute or an unrequested parallel app plus HTML report