agent-creator-skill

name	agent_creator_skill
description	Create new agents, improve/optimize existing agents (both Python class and HTML prompt), and evaluate agent quality — the full agent lifecycle in this framework. Use whenever the task involves authoring a new agent, editing/improving an existing agent or its prompt, or evaluating/scoring an agent. MetaAgent uses it to orchestrate the create→evaluate→improve loop across sub-agents.
version	1.1.0
type	["orchestrator","worker"]
category	meta
requirements	["cpu"]
metadata	{}

Agent Creator

A single skill for the full lifecycle of agents: creating new ones, improving existing ones (class and prompt), and evaluating their quality. An agent in this framework is a thin Python class over the shared base Agent, usually paired with an HTML prompt (for tool-calling agents) and a config.

At a high level, building a good agent is a loop: decide what it should do → pick the agent type → write a thin class + a focused prompt from the templates → run it on realistic tasks → evaluate → improve the prompt/class → repeat.

How this skill is used — four roles, one body of knowledge

• MetaAgent (orchestrator role) — drives the create→evaluate→improve loop, dispatching the sub-agents. See Orchestration.
• agent_generate_agent — reads Creating an agent.
• agent_optimize_agent — reads Improving an agent (this is where most of the value is — prompt tuning).
• agent_evaluate_agent — reads Evaluating an agent.

The sub-agents are headless: each runs one phase autonomously and returns a result. There is no human-in-the-loop review.

Reference templates — read before writing

Start from the bundled templates instead of writing from scratch:

• references/tool_calling_agent_template.py — a thin tool-calling agent class (the common case).
• references/procedural_agent_template.py — a deterministic, code-driven agent (no LLM loop, no prompt).
• references/html_prompt_template.html — the HTML prompt skeleton for a tool-calling agent.

Read the relevant template(s) first, copy, then adapt. They already encode the current architecture and the template-variable contract.

Framework conventions (read once)

An agent has up to three files:

• {extension_root}/agent/{name}.py — the Python class (REQUIRED).
• {extension_root}/prompt/{name}.html — the HTML prompt (REQUIRED for tool-calling agents; procedural agents omit it).
• {extension_root}/configs/agents/{name}.py — the config dict.

Registration is automatic via a hook: after writing the files, include the Python file path in your done_tool reasoning — the agent_registration_hook locates and registers it. The class name in done_tool reasoning helps it resolve.

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Choosing the agent type

• Tool-calling agent (default): reasons and acts step by step, choosing tools/skills dynamically each step. Use it for open-ended or multi-step tasks. It has a Python class + an HTML prompt, and it inherits the base loop. → tool_calling_agent_template.py + html_prompt_template.html.
• Procedural agent: a fixed, deterministic pipeline (read → process → report) expressed in code with direct tool calls — no step-by-step LLM planning, no prompt. It subclasses ProceduralAgent and implements run_procedure; it never overrides __call__. → procedural_agent_template.py.

When unsure, prefer a tool-calling agent — it's the more general, more capable form.

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Creating an agent

The class is THIN — inherit, don't reinvent

The base Agent already implements the standard think-and-act loop (__call__) and the context builder (_get_agent_context, _get_messages, _think_and_act). A well-formed tool-calling agent inherits all of it and only supplies:

• its identity fields (name, description, metadata, enable_evolving),
• an __init__ that sets prompt_name (must match the HTML prompt's <meta name="name">),
• a thin __call__ that delegates to super().__call__(...).

Do NOT override _get_agent_context, _get_messages, or _think_and_act unless the agent genuinely needs bespoke behavior — reviewers treat unnecessary overrides as a defect. The only common reason to put real logic in __call__ is an agent that must register a produced artifact: it calls super().__call__(...), then fires a registration hook on the result (see the variant in tool_calling_agent_template.py).

Steps:

1. Read tool_calling_agent_template.py, copy it to extension/agent/{name}.py, rename the class, and fill name / description (state what it does AND when to use it) / prompt_name.
2. Write the HTML prompt (next section).
3. python -m py_compile /abs/path/{name}.py; then put the .py path in done_tool reasoning to register.

Writing the HTML prompt (this is where agent quality lives)

Copy html_prompt_template.html to extension/prompt/{name}.html, set <meta name="name"> to the agent's name, and fill each block. The prompt is the agent's brain — treat it with the same care as a skill.

Structure (do not break it):

• system: profile, language-settings, project, input-rules, constraint-rules, task-rules, context-rules, response-protocol.
• user: an <agent-context> container holding task / constraints / step-info / memory / (todo) / workspace / (errors), with <tool-context>, <skill-context>, <connector-context> as siblings of <agent-context> (NOT nested). The CSS/renderer depends on this container-vs-sibling layout.

What each block is for (fill the agent-specific ones; keep the shared ones roughly as the template has them):

• profile (agent-specific) — who the agent is and its core behavior; explain the WHY, not just rules.
• language-settings (shared) — working language and "reply in the request's language".
• project (agent-specific) — the paths this agent may read/write and its permission posture (read-only vs edit). This is a real guardrail — say exactly where it may write.
• input-rules (agent-specific) — what each context sub-module means and which inspect_* tool this agent uses.
• constraint-rules (shared) — the resource-budget / urgency-tier contract (NORMAL / TIGHT / CRITICAL).
• task-rules (agent-specific) — the agent's objective and when to call done_tool.
• context-rules (shared) — how memory is presented, and that it must use only the listed tools/skills/connectors (ignoring any not loaded).
• response-protocol (shared) — that it acts by calling tools natively (not by emitting a JSON plan), and signals completion only via done_tool.
• agent-context + tool/skill/connector-context (shared frame) — the live-state and capability slots; only the template variables below go here.

Shared blocks & modules. The built-in default agents in agentevolver/prompt/default/ factor the shared blocks (language-settings, constraint-rules, context-rules, response-protocol, agent-context) into agentevolver/prompt/module/*.html, referenced with <module src="../module/NAME.html"></module> (the server inlines them into the message; prompt.js inlines them for browser viewing). Generated agents keep these blocks inline — do NOT use <module src> in an extension/prompt/ file: module src is resolved relative to the prompt file, so ../module/... only exists under agentevolver/prompt/default/ and would fail to load from extension/prompt/.

Template-variable contract — use only the variables the base context builder provides, spelled exactly: {{ task }}, {{ constraint_text }}, {{ step_info }}, {{ memory_context }}, {{ workspace }}, {{ errors }}, {{ todo }}, {{ available_tools }}, {{ available_skills }}, {{ available_connectors }}, plus the system-side {{ extension_root }}, {{ workspace_root }}. Inventing a variable leaves an empty slot; misspelling one silently drops that context.

Response contract — native tool calls (NOT a JSON plan): the base loop turns the agent's capabilities into native tools and reads the model's tool_calls each step; it does NOT parse a JSON plan/output-schema from the text. So response-protocol must tell the agent to act by calling tools and to finish only by calling done_tool. (Older prompts used a plan/output-schema JSON contract — that is obsolete; do not reintroduce it.)

Writing principles (borrowed from good skill authoring):

• Prefer the imperative. Define concrete rules, not vague directives.
• Explain the WHY. Modern models have good theory of mind — when you explain why a rule matters, they generalize instead of following it brittly. All-caps ALWAYS/NEVER and rigid structures are a yellow flag: reframe as reasoning.
• Keep it lean — every line should earn its place. Remove instructions that don't change behavior.
• Make the profile and task-rules say clearly what the agent is for and how it should approach work.
• Draft it, then reread with fresh eyes and cut/clarify.

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Evaluating an agent

Call inspect_agent_tool on the target for its registry facts (registered / instantiated / version / file paths). Score across five dimensions (0–20 each):

1. Interface Compliance — @AGENT.register_module, inherits Agent, has name/description/metadata/enable_evolving; cleanly inherits the base loop. Tool-calling agents must not override __call__; procedural agents subclass ProceduralAgent and implement run_procedure.
2. Code Quality — clean, valid, no dead code; lifecycle hooks come from the inherited loop, not re-implemented.
3. Prompt Quality — HTML present (tool-calling) with the required sections, the container-vs-sibling agent-context layout, correct template variables, and a response-protocol that drives native tool calls (no obsolete JSON plan/output-schema). Auto-pass for procedural agents (no prompt).
4. Integration — inspect_agent_tool shows Registered + Instantiated.
5. Task Execution — a valid execution path: a tool-calling agent with a valid prompt_name inheriting the loop, or a ProceduralAgent implementing run_procedure.

For an empirical check, MetaAgent can dispatch the agent on a sample task and inspect the result.

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Improving an agent

Most agent improvement is prompt improvement. The target is named in the task. Call inspect_agent_tool FIRST for its file paths and enable_evolving — if enable_evolving=False, the agent is frozen; do NOT edit it, report and stop. (The built-in default agents are all frozen; the optimizer edits generated agents under extension/, which keep every block inline.)

• Read the Python and HTML before editing. Decide whether the fix is in the prompt (behavior, rules, reasoning — most common) or the class (a real code bug).
• Make the smallest correct change. Preserve @AGENT.register_module, name, and the prompt's agent-context structure and template variables.
• If you ever edit a agentevolver/prompt/default/ agent and see a <module src="../module/NAME.html"> tag, that block is a shared module used by many agents — editing the module file changes all of them; to change one agent only, inline the block into that file first.
• Keep the class thin — prefer fixing the prompt over adding loop overrides. If you see an unnecessary override of _get_agent_context/_think_and_act, that's a candidate to remove.
• Apply the prompt writing principles above: explain the why, cut dead instructions, sharpen the rules the agent kept getting wrong.
• Verify with py_compile (and that the HTML still has valid template variables), then re-register by putting the edited file path in done_tool reasoning.

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Orchestration (for MetaAgent)

1. Generate — dispatch agent_generate_agent with the intent; it writes the class/prompt/config from the templates and registers.
2. Evaluate — dispatch agent_evaluate_agent (optionally after a sample run) to score.
3. Improve — dispatch agent_optimize_agent with the evaluation; it edits (usually the prompt) and re-registers.
4. Repeat until the agent is good.

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Reference files

• references/tool_calling_agent_template.py — thin tool-calling agent class.
• references/procedural_agent_template.py — deterministic procedural agent.
• references/html_prompt_template.html — HTML prompt skeleton (structure + template-variable contract).