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

Annotations already cover read-only/idempotent/non-destructive, but the description adds real behavioral context beyond them: it discloses that results include attachment URLs, explains parent_comment_id semantics for roots vs live parents, and warns that the content is untrusted public text to report on but never execute. That prompt-injection caution is exactly the kind of guidance annotations cannot convey.

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 front-loaded sentences with no padding: purpose first, then a return-shape detail, then a safety instruction. The middle sentence concerns a return field rather than the call itself, but it earns its place given there is no output schema.

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 read-only single-record tool with no output schema, the description supplies the key return details (attachments, parent linkage) and a security caveat, which is enough to call it correctly. It is complete for its complexity, though return-value coverage is only partial.

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 100%, so both required UUID parameters are already documented in the schema, making 3 the baseline. The description's mention of parent_comment_id refers to a return field rather than an input parameter, so it adds no meaning beyond the schema for the actual inputs.

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 (read) and resource (one live comment on a specific request) and adds attachment-URL scope, which naturally distinguishes it from list_feature_comments. It does not, however, explicitly name or contrast a sibling, so differentiation is inferred rather than stated.

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: 'one live comment' suggests single-record retrieval as opposed to the list_* siblings, but there is no explicit when-to-use, when-not-to-use, or named alternative. An agent can infer the context but is given no routing guidance.

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