The workspace now holds .pi/SYSTEM.md and .pi/APPEND_SYSTEM.md and nothing else.
SYSTEM.md is rewritten for what is actually deployed. The version committed in
07dd648 described five tools that will not exist until phase 3; shipping it would
have invited the model to call tools it does not have. The capability section now
states plainly that the agent has no tools and that every fact arrives in the
request. The phase-3 target, including the full tool-bearing launch contract, is
recorded in the plan as §4b together with why each part cannot be enabled sooner.
profile.toml likewise describes the deployed configuration rather than the target,
so that deploy-scenario.sh validates against reality and the path check means
something.
Recovered from the retired SKILL.md and folded into SYSTEM.md: the rule that the
current request's schema and length limits override everything else, and that a
JSON task returns exactly one JSON value with no fences. Phase 0's four prompt
types all depend on it, and it was the one part of that file not already covered.
Measured before and after on the real workspace, with flags read from the code
rather than transcribed (docs/evidence/2026-08-27-curator-phase0-prompt.md):
- expert coding assistant framing: present -> gone
- pointer to pi's own documentation: present -> gone
- the 64-line media policy: absent -> present
- workspace AGENTS.md: loaded -> blocked
- parent-directory AGENTS.md: LEAKED -> blocked
- <available_skills>: absent both times
Two things this confirms on the production configuration rather than a synthetic
probe. --skill was genuinely a no-op: it pointed at a real 64-line SKILL.md and
the skills block was still absent, because pi emits it only when a tool named
read is active and --no-tools deactivates everything. And --no-context-files is
the only switch that stops parent-directory pollution: a marker planted in
/home/claw/pi-workspaces/AGENTS.md reached the prompt before and not after.
Deleting the now-dead AGENTS.md and SKILL.md from the workspace changed the
prompt length by zero bytes, which is the proof that they were dead.
README corrected. Its table cited 960 characters as Curator's system prompt after
the change; that figure came from a few-line stub SYSTEM.md in the isolation
probe, and the real prompt is 3539 -- larger, not smaller. Presenting the stub
measurement as Curator's was misleading, and "72% smaller" was wrong. The prompt
grew because roughly 1.9 KB of pi scaffolding was replaced by domain policy that
had never loaded at all. The mechanism claim is unaffected.
Establishes this repository as the authoritative source for Pi agent
configuration across scenarios, starting with the documentation layer.
Key verified findings (probe harness included, zero model tokens):
- The skills section of the system prompt is emitted only when an active tool
named 'read' exists (system-prompt.js:59,113). Therefore --no-tools silently
makes every SKILL.md unreachable and --skill a no-op.
- registerTool accepts a plain JSON Schema object, so tool definitions can be
served from a backend instead of duplicated in TypeScript.
- An extension can shadow a built-in tool by name, which is how a dedicated
agent gets a path-restricted 'read' while still satisfying the rule above.
- .pi/SYSTEM.md replaces pi's coding-assistant prompt, but the replacement
branch contributes neither the tool list nor the guidelines.
- Without --no-skills/--no-extensions, user-global resources leak into every
scenario; probed leak was find-skills, modsearch, summarize.
Measured effect of the full baseline: system prompt 2619 -> 960 characters,
coding-assistant framing and pi-docs paths removed, skill finally reachable.
Secrets are guarded by scripts/verify-no-secrets.sh, installed as a pre-commit
hook. Backups deliberately live outside the repository.
Kai