Repair CHIP headers

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Adds real behavioral context beyond the annotations: dry-run preview by default, a confirm gate for the actual write, and a backup of the .acf file. This meaningfully softens the destructiveHint=true profile. It does not explain what happens on repeated runs despite idempotentHint=false, so not quite a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences with no filler: the action and targets come first, followed by the setacf rationale and the safety workflow. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a destructive, no-output-schema mutation tool, the description covers the key agent needs: what it rewrites, the preview/write gate, and the backup. Return details are unnecessary with no output schema; only the non-idempotency behavior is left unaddressed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so all five parameters are already documented. The description restates the confirm and backup semantics already present in the schema and adds no new syntax or format detail, making baseline 3 correct.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (Rewrite) plus the exact resource and the malformed forms it targets (bare "CHIP " or shell-escaped names) and the canonical output form. It also distinguishes itself from the setacf siblings by explaining that setacf is append-only and cannot perform this fix.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Clearly signals when to reach for this tool (malformed CHIP headers that setacf cannot repair) and establishes the preview-first workflow with confirm:true required to write. It stops short of naming explicit alternatives or when-not-to-use conditions, but the routing context is strong.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.