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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the description is not carrying the safety burden. It still adds genuinely useful context beyond them: 'Public, no credential' removes auth uncertainty, and the ordering contract ('`discussion_seq` order after `after`, oldest first') tells the agent exactly how results are sequenced.

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 short sentences, each doing distinct work: purpose, access model, result ordering, then pagination. The purpose and access constraint are front-loaded and there is no redundant phrasing.

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 no output schema, the description correctly fills the gap by naming `next_cursor` and `discussion_seq` as return fields and explaining how to chain them. It does not describe what a comment record contains beyond the sequence number, which is a minor remaining gap for a read tool of this simplicity.

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, and the description earns above that by linking the `after` parameter to the `next_cursor` output value and restating the oldest-first ordering that the schema's 'after this discussion_seq' does not make explicit. `limit` and `post_id` are left entirely to the schema.

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 ('Read a listing's discussion') and clarifies the unit returned ('The listing's comments'), which separates it from get_comment and post_comment in the sibling set. It never names an alternative explicitly, so it falls short of full sibling 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?

The pagination instruction ('save `next_cursor` and pass it as `after` next time') gives clear guidance for the follow-up call, but there is no statement of when to use this tool versus get_comment or get_listing. Usage for the first call is only implied by the tool's purpose.

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