Find user

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds useful behavior beyond them: the fact that results are user IDs usable for mentions (<@ID>) and DMs, and that omitting the query switches to a paginated listing of active people. It omits rate limits or auth needs, but those are minor here.

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 tight sentences, front-loaded with the search behavior and then the no-query listing behavior. Every clause carries information; nothing is redundant filler.

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 3-param, zero-required read tool it covers both modes, identifier formats, and pagination, and it explains the return value (user IDs for mentions/DMs) despite there being no output schema. Only minor details like rate limits or result ordering are 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 description coverage is 100%, with limit, query, and cursor each documented in the schema (including the 50/200 limit nuance). The description only restates query optionality and cursor usage, so it adds little beyond the schema; baseline 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 (look up) and resource (people) plus the accepted identifier formats (name, @handle, email). It also distinguishes the two operating modes (search vs. list) within a single sentence, so an agent immediately understands what the tool does and how its behavior changes.

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 to supply a query to search and to omit it to page through active people, and names nextCursor for pagination. It does not mention alternatives (e.g., whoami or message-search tools), but those are not true substitutes for user lookup, so the guidance is clear though not exhaustive on when-not to use it.

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