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

The read-only and non-mutating statements largely repeat the annotations. However, the description adds useful operational context beyond them: the results are public data and each request costs 1 credit.

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 front-load the purpose and then convey data scope, safety, and cost. The definition is compact and easy to scan without unnecessary parameter recitation.

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 simple three-parameter read-only listing tool, the description, annotations, and fully documented schema provide enough information to invoke it correctly. Explicit sibling routing and some indication of the response shape would improve completeness, particularly because no output schema is supplied.

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?

The schema fully documents all three parameters, including accepted subreddit formats, the count range and default, and cursor-based pagination. The description adds no parameter meaning beyond that coverage, so the baseline score 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?

The opening sentence specifies the action, resource, and scope: listing recent comments within a subreddit. This broadly separates it from post and user-comment tools, but it does not explicitly distinguish it from close alternatives such as reddit_search_comments or reddit_list_user_comments.

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 subreddit and recency scope imply when the tool is useful, but there is no explicit when-to-use or when-not-to-use guidance. The agent must infer when to choose this tool rather than searching comments or listing a user's comments.

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