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

Behaviors are covered by annotations (readOnly, idempotent, openWorld, non-destructive), yet the description adds real context beyond them: ranking is by number of matching words, the search spans the whole index, the return is entry titles with URLs, and it is free (0 credits). That ranking/cost disclosure is genuinely useful and not present in structured fields.

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?

Four sentences, front-loaded with the core purpose and scope, then usage, then return shape, then cost. Every sentence carries distinct information with no redundancy.

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 compensates by stating the return shape (entry titles plus URLs) and the natural next step (pass a URL to wex_define). Annotations handle the safety profile, and the cost/ranking details round out everything an agent needs to invoke it correctly.

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 the baseline is 3. The description reinforces query semantics (multi-word title matching, ranked by match count), which slightly exceeds the schema, but it adds no syntax, format, or default detail beyond what the schema already documents for 'query' and 'limit'.

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), resource (Wex legal-encyclopedia entries), and matching scope (words in titles, over the whole 5,600-entry index). It also implicitly distinguishes itself from wex_define (which returns the definition) and wex_browse, so an agent can route between the three without opening schemas.

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?

Explicitly says when to use it ('when you do not know the exact term') and gives a concrete example of broadening via 'possession'. It also names wex_define as the follow-up for definitions, but gives no explicit exclusion against wex_browse, so differentiation is implied rather than stated.

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