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

Annotations already declare read-only, open-world, non-idempotent, non-destructive behavior. The description adds meaningful context beyond that: answers come from server-side code rather than a model, refused asks are not guessed, sources are cited, UTC clock is used, and a card link is returned. That is useful behavioral disclosure, though the marketing framing dilutes it.

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?

The text is padded with self-promotional claims ('one of the proven skills with the most evidence', 'rated proven on a-to-mind.com') that do not help an agent select or invoke the tool. The useful facts are buried among parentheticals and marketing copy.

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?

With no output schema, the description should more clearly explain what the text and raw_data responses contain beyond a link to a card. It covers refusal behavior and deterministic answer sourcing, but leaves the return shape underspecified.

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 description coverage is 100%, so both parameters are already documented. The description offers example asks but no additional syntax, constraints, or raw_data semantics beyond what the schema provides. 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?

The description gives concrete example asks (synonyms, spelling, rhymes) that make the tool's function understandable, though the phrase 'Words and the world' is vague. It does not explicitly distinguish itself from potentially overlapping siblings like skill_define or skill_translate, so it stops short of a 5.

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?

There is no guidance on when to use this tool versus alternatives, nor any explicit exclusions beyond 'an ask the skill does not take is refused.' The examples imply usage but do not constitute routing guidance.

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