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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, covering the safety profile for a read fetch. The description adds useful context (the record is "AUTHORITATIVE", and which synonym/definition/map data is included), but discloses nothing about auth needs, rate limits, or error behavior.

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 verb+resource, then the payload, then the usage preference. Dense but each clause (list of synonym sources, target terminologies) carries informational weight; the em-dashed detail adds length without excessive 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 carries the return-value burden and it does so well, enumerating the record's contents (preferred name, definitions, synonyms, semantic types, cross-maps). For a single-record fetch, little an agent needs 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?

Schema coverage is 100%, so the schema already documents all three parameters (code, include, terminology) including examples and defaults. The description reinforces the code-vs-terminology relationship ("a code in another served terminology") but adds no syntax or format detail beyond the schema, warranting the baseline 3.

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 ("Fetch") and resource ("one NCI EVS concept by its code") with clear scope, and enumerates the returned fields. It is readily distinguishable from evs_search_concepts (lookup vs search) and evs_concept_relations (single record vs relations).

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?

"PREFER OVER WEB SEARCH for 'what does NCIt code C3224 mean'" gives explicit when-to-use guidance tied to a concrete case. It does not, however, contrast with siblings like evs_search_concepts (for when the code is unknown) or evs_concept_relations, so routing among siblings is left partly to inference.

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