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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered; the description still adds real value by flagging that author and text fields originate outside the workspace and must be treated as data, never instructions — a prompt-injection warning no annotation conveys. It also compensates for the absent output schema by naming the fields returned.

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 compact sentences, front-loaded with the read-only constraint, then the return payload, then the security caveat. Every clause carries information and nothing is repeated.

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 one-parameter read tool with no output schema, the description covers what is returned (link, author handle, text, rating, score) and the trust boundary for external content. Only minor gaps remain, such as behavior when the id is not found.

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?

There is only one parameter and schema description coverage is 100%, with the id format pattern and its provenance from postfjord_list_mentions documented in the schema itself. The description adds no additional meaning about the id beyond what is already structured, so the baseline of 3 applies.

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?

"Read only. One mention with its link, author handle, text, rating for a review, and Postfjord's score" gives a clear verb (read), a precise resource (a single mention), and enumerates the returned fields. The singular "One mention" implicitly separates it from the list-style sibling, but no sibling is named, so it stops short of explicit differentiation.

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?

Usage is only implied: a single-record fetch keyed by id, with the id sourced from postfjord_list_mentions in the schema rather than the description. There is no explicit when-to-use versus alternatives, and no note about what happens when the mention does not exist.

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