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

No annotations, so the description carries full burden. It discloses the LIKE matching behavior, which is useful, but says nothing about whether it's read-only, rate limits, output shape, or pagination of the multi-result search.

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?

A single tight sentence with no filler; front-loads the action and resource. Could be a touch more informative without bloat.

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 output schema present, return values needn't be explained. But with no annotations, no param coverage, and a sibling that overlaps, the description is thin on the discrimination and behavioral context an agent needs.

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 0%, which is quite low. The description clarifies the 'query' parameter semantics (matches against username via LIKE), compensating partially for the undocumented 'query'. But 'limit' is undocumented in both schema and description. A 3 reflects that one parameter is explained while the other is left bare.

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?

Clear verb+resource: search users by username, with LIKE matching noted. But it doesn't distinguish itself from sibling mcp_get_user, which also retrieves a user, leaving the agent to infer the difference.

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?

No when-to-use guidance and no mention of the alternative mcp_get_user. The 'LIKE' hint is a small behavioral clue but not usage routing.

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