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

Annotations already mark this as read-only and non-destructive, but the description adds critical behavioral details: every sort value returns only posts and never comments or media, response size is about 5 KB with ~2 second latency, and it is faster than the global search. This goes well beyond what annotations provide and corrects a misleading implication of the sort parameter.

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?

Every sentence in the description earns its place: scope and pagination, return fields, the sort caveat, performance comparison, and the routing to a sibling tool. The most important distinguishing information is front-loaded.

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?

Given the rich schema, output schema, and annotations, the description fully covers what an agent needs to select and invoke the tool correctly. It includes return field details, pagination behavior, performance expectations, the surprising sort behavior, and when to use sibling tools.

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 input schema has 100% coverage, so parameters are already documented. The description adds extra semantic value by clarifying that the sort parameter's values all produce posts-only results and by explaining that cursor is the pagination token. This lifts it above the baseline.

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 the tool searches within one subreddit and returns matching posts, with a cursor token for pagination. It also distinguishes itself from get_reddit_search, which searches all of Reddit, so an agent can tell them apart.

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 explicitly names get_reddit_search as the alternative for all-of-Reddit searches and explains the difference in scope and pagination mechanism. It also points to get_reddit_post_comments for retrieving replies under a result, giving clear routing guidance.

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