user_mention_suggestions

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

There are no annotations, so the description carries the full burden. It reveals that the tool returns a recent list of candidates and gives the exact item shape, but it does not mention authentication requirements, result limits, ordering, or any side-effect profile. The 'Returns' wording implies a read-only operation, but that is not stated explicitly.

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?

The description is a single focused sentence that communicates purpose, context, and return format with no filler. Every piece of information contributes to invoking the tool correctly.

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 zero-parameter tool with a simple output shape, the description is largely sufficient: it states the purpose, the usage context, and the return structure. Minor gaps remain around the meaning of 'recent', maximum result count, and authentication expectations, but none are critical for basic invocation.

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?

The input schema has zero parameters and 100% schema description coverage, so there are no parameter semantics left undocumented. The description adds no parameter details, but none are needed; this is the baseline for a zero-parameter tool.

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 names a specific resource ('@-mention candidates') and a specific use context ('comment / DM composer'), and it states the return shape. This makes it clearly distinguishable from siblings like search_suggest or related_tags.

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?

The description explicitly says when to use the tool: when obtaining recent @-mention candidates for the comment or DM composer. It does not list exclusions or alternatives, but the context is clear enough for an agent to select it appropriately.

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