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

With no annotations provided, the description carries the burden and does disclose two important behavioral traits: it returns empty when the word is unknown or no thesaurus is loaded, and it is labeled 'internal'. It does not describe rate limits or return structure, but for a read-only lookup those are minor omissions.

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?

One sentence, front-loaded with a bracketed category tag, then the resource definition, then scope clarification, then the empty-result note and the page reference. No filler; every clause adds information.

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?

The description covers what the tool returns (synonyms + IS-A terms), the failure mode (empty for unknown/unloaded words), and the backing store (WordNet). It does not explain the empty-list return shape or whether the word is tokenized, which would be helpful given the absent output schema, so it is complete but not exhaustive.

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 0% for the required 'word' parameter, so baseline would be low; however, the description does specify that the parameter is a single word and that the result set is its synonyms and broader terms, which compensates somewhat. It does not document the maxLength (4000) or casing behavior. With one parameter, a 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 (FIND), a specific resource (WordNet synonyms and IS-A terms), and the exact scope ('the words that stand with it'). It also names the sibling it complements, 'define', and cites the underlying data source (WordNet), so an agent can distinguish it from 'search', 'define', or 'lookup' without opening the 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?

The description makes the usage context clear (lexical retrieval of synonyms and broader terms for a single word) and names the alternative surface, the GET /thesaurus page. It does not explicitly state when-not-to-use or which sibling to pick instead of define/lookup, 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.