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

Annotations already mark this as read-only and non-destructive. The description adds meaningful behavioral detail: REJECTED mentions are excluded by default, sub-30 relevance mentions are hidden, and includeLowRelevance overrides the hidden default. This goes beyond what annotations alone provide.

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?

Three compact sentences with no filler. The core purpose is front-loaded, default behavior is stated clearly, and available filters are enumerated efficiently.

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?

The description covers the core behavior, default filters, override behavior, and filter surface. Combined with the rich input schema, output schema, and read-only annotations, the agent has enough context. The slight ambiguity around includeLowRelevance and REJECTED exclusion keeps it from a perfect score.

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 100%, so the baseline is 3. The description does add default-behavior context, especially for includeLowRelevance, but the phrase 'set includeLowRelevance to see everything' is slightly misleading because that parameter only controls the <30 relevance filter, while REJECTED exclusion is a separate statuses concern.

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 clearly states a list operation, the resource ('mentions'), the account scope, and the specific sources included. It also adds a distinguishing detail (AI-scored relevance 0-100) that separates it from siblings like count_mentions or update_mention_status.

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 gives clear context for when the tool is useful: listing account-matched mentions across multiple platforms, with filtering and default exclusions. It doesn't explicitly name sibling alternatives or say when not to use it, so it stops short of a 5.

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