| name | context-size |
| description | Estimate the total prompt size that will be sent to an AI agent when processing an Evoloop story — warns if approaching model context limits |
| argument-hint | <US-XXX> |
| allowed-tools | ["Read","Glob","Bash(wc *)","Bash(jq *)"] |
Context Size Analyzer
Input
Story ID from $ARGUMENTS. If empty → print usage. If missing → list stories.
Calculation
Read story JSON for stage, then measure all files build_prompt() would assemble:
| Component | File | Notes |
|---|
| Agent prompt | agents/{agent}.md | build→builder.md, review→reviewer-test.md, deploy→deploy.md |
| Story JSON | prd/<ID>.json | |
| Story tracker | prd/<ID>.md | |
| Runbook | .plan/runbook.md | |
| Traceability | .plan/traceability.md | |
| Handoff notes | .log/run-<run-id>/handoff-notes.md | May not exist |
| Context files | From story's context.files array | If present |
Size each with wc -c.
Model Limits
| Model | ~Tokens | ~Bytes |
|---|
| Claude (Opus/Sonnet) | 200K | ~800KB |
| Gemini 1.5 Pro | 1M | ~4MB |
| Codex (GPT-5) | 200K | ~800KB |
(1 token ≈ 4 bytes rough estimate)
Output
=== Context Size: <ID> (stage: <stage>) ===
Agent: <agent>.md
| Component | File | Bytes | KB | % |
...
| TOTAL | | | | 100% |
Model Limits: Claude X/800KB | Gemini X/4000KB | Codex X/800KB
Warn if >50% of any model limit. Missing files → "NOT FOUND", 0 bytes. >500KB → prominent warning.
