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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, so the safety profile is covered. The description adds sorting order (newest first), the returned fields, the no-watchId fallback, and an auth prerequisite ('Needs a free SnoopScan key') – useful context beyond the annotations.

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?

Front-loaded with the core action, then filters, then edge-case behavior and auth note. The embedded enum lists are long but informative; structure is efficient with little waste.

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 an output schema present, return values needn't be spelled out, and the description covers filtering, ordering, fallback, and auth. Only the limit/pagination behavior is left unaddressed.

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 0%, so the description must carry the load. It documents category and status enum values, the watchId scoping, and platform filtering – but the `limit` parameter and its default (20) are never mentioned.

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 and resource ('List the mentions this account's watches have found') with scope detail (newest first, each with category and deciding phrase). This clearly distinguishes it from mutation/other siblings like markMention or watchMentions.

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?

Explains the filtering conditions (watchId, category, platform, status) and the no-watchId fallback behavior. However, it does not explicitly contrast with variants like testMentions or watchMentions, so the alternative-selection guidance is implicit rather than stated.

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