context-checkup

name	context-checkup
description	Audit what auto-loads into an agent session's context window and suggest lean, reversible fixes to cut startup tokens.
disable-model-invocation	true
type	flow
license	MIT
metadata	{"author":"Francesco Borzì","version":"1.2"}

Context checkup

Find what loads automatically into the session's context at startup, quantify it, and propose reversible trims ranked by payoff — shrink the startup context window by cutting what isn't worth its tokens. Read-only — measure and recommend; change settings only on explicit approval.

Mental model (spend attention top-down)

Cost hierarchy, biggest first:

1. MCP tool schemas — large, but deferred by tool search. Only a problem if tool search is OFF.
2. Always-on text — CLAUDE.md/AGENTS.md chain, @imports, and skill/agent/command descriptions (every available one's description loads every session).
3. MCP server instructions — load per enabled server at startup; a chatty preamble can dwarf its tool names.
4. MCP tool names — ~10 tokens each. Cheap; 30 names ≈ 300 tokens isn't worth a recommendation.

Rules: measure, never guess — wc/count, then attach a rough token figure to each finding. Rank by tokens-saved × reversibility. Distinguish auto-loaded from lazy-linked (nested AGENTS.md referenced from a parent are not loaded — don't flag them).

Tool-name counts, the skills/agents/commands lists, and tool-search status come from the session's system-reminders, not disk — read them from your own context.

Checklist

0. Verify tool search is on first. If ENABLE_TOOL_SEARCH is disabled, MCP schemas load eagerly and every "names are cheap" conclusion flips. Check this before anything else.

1. Always-on docs. Measure the CLAUDE.md/AGENTS.md chain: project file + every parent dir up to root + global ~/.claude/CLAUDE.md. Expand @import lines (recursive). wc -w each.

2. Descriptions (often the largest unexamined chunk). Skim the in-session lists of skills, subagent types, and slash commands — their descriptions are always loaded. Many rarely-used entries = standing cost.

3. MCP servers. From .mcp.json + settings, list enabled servers. Count tool names per server; note any server with long instructions. Flag servers irrelevant to the user's work.

4. Enablement levers. Read ~/.claude/settings.json, project .claude/settings.json, .claude/settings.local.json. Check enableAllProjectMcpServers, enabledMcpjsonServers, enabledPlugins. Precedence: managed > local > project > user. Each plugin can pull in MCP servers, skills, agents, hooks.

5. Memory. Size of MEMORY.md index.

Output

A short sizes table (source → ≈ tokens → auto-loaded? → relevant to user's work?), then a prioritized action list. For each action give the exact setting/file edit, the rough savings, and how to reverse it (prefer per-session toggles). Skip anything under ~a few hundred tokens unless asked to be exhaustive. Then ask before editing.

Useful probes

# always-on doc chain (run from project root; also check parent dirs + ~/.claude/CLAUDE.md)
for f in CLAUDE.md AGENTS.md ../CLAUDE.md ~/.claude/CLAUDE.md; do [ -f "$f" ] && wc -w "$f"; done
# enabled MCP + settings
cat .mcp.json; cat .claude/settings.json .claude/settings.local.json ~/.claude/settings.json 2>/dev/null