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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral fact - results are capped at 10 matches - but says nothing about ranking, what happens when more than 10 match, or pagination/truncation 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?

Two short sentences, front-loaded with the action and the accepted inputs, with no redundant or filler wording.

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?

For a one-parameter read-only lookup the definition is serviceable, and annotations cover safety. However, with no output schema, the description never indicates what a match contains (id, email, name) or whether ordering is deterministic, so the agent knows the result count limit but not the result shape.

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?

With a single parameter at 100% schema description coverage, the schema already documents that 'query' accepts email, name or id with partial matching. The description's field list duplicates that, adding no syntax or format detail beyond the schema.

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 states a specific verb and resource ('Find users') plus the searchable fields ('email, name or id'), which is clearly distinct from a single-record fetch. It doesn't explicitly name siblings like get_user or list_users, so the boundary between search and direct lookup is only implied.

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?

Usage is implied rather than stated: 'Find' plus 'up to 10 matches' suggests a fuzzy lookup, so an agent can infer this is not the right tool when it already holds an exact user id. There is no explicit when-to-use/when-not guidance or pointer to get_user or list_users as alternatives.

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