Say whether a draft sounds like the user

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

With no annotations, the description carries the full burden and does so well: it discloses the prerequisite (a fingerprint), the mechanism (compares sentence rhythm, punctuation habits, and register), the non-destructive behavior ('nothing is rewritten'), and operational traits ('Deterministic, free, and local'). It also warns about interpretation ('a trait outside the range can be good writing that is not theirs').

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?

Front-loaded with the core purpose and no dead preamble. It runs long, and the second clause ('or to check whether text matches their voice') partly restates the opening, so it is efficient but not maximally tight.

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?

An output schema exists, so return values need not be explained. The description fills the remaining gaps an agent needs: the fingerprint prerequisite, determinism/local/free operation, the non-destructive nature, and what the tool actually compares. Nothing material is missing.

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?

There is a single parameter with 100% schema description coverage, so the schema already documents 'text' fully. The description's note that a trait listing is per-trait and that a paragraph or more is needed roughly mirrors what the schema already says, adding little beyond it. Baseline 3 is appropriate.

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 and resource: measure a draft against the user's own writing and report where it stops sounding like them. It further distinguishes the tool from the rewriting siblings by clarifying that 'Drift is not slop' and 'nothing is rewritten', so an agent can tell it apart from chop without opening a schema.

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?

Gives concrete usage contexts ('before handing over a draft you wrote for them, or to check whether text matches their voice') and an explicit prerequisite (a fingerprint the user makes by running slop-chop voice fingerprint). It lacks an explicit when-not or a direct comparison against named siblings check/chop/presets, so it falls short of a 5.

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