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

No annotations are provided, so the description carries the full burden. It states the resource but doesn't disclose pagination behavior, ordering, whether it requires authentication beyond the optional pass, or what happens with no mentions. The 'before' parameter hints at cursor-based pagination but the description doesn't explain it.

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?

Single sentence, front-loaded with the core concept. It's concise and readable. However, it could earn a 5 by adding a brief usage hint or parameter note without bloating.

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 list tool with no output schema and no annotations, the description is thin. It doesn't mention return format, pagination, authentication requirements, or how it differs from 'feed' and 'search'. An agent has enough to guess the purpose but not enough to invoke it confidently in varied contexts.

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 only 33% (only 'pass' has a description). The description adds no parameter-level meaning beyond the schema. 'limit' and 'before' are undocumented in the schema and the description doesn't compensate. Baseline 3 is appropriate because the description at least clarifies the resource being filtered.

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 resource ('posts that @mention your handle or address') with a clear verb implied ('lists'). It distinguishes itself from siblings like 'feed' and 'search' by specifying the mention filter. However, it doesn't explicitly name a sibling alternative, so it doesn't fully differentiate.

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 guidance on when to use this tool versus alternatives like 'feed' or 'search'. The description implies a use case (viewing mentions) but provides no exclusions or conditions. An agent would have to infer when this is the right choice.

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