search_communities

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

No annotations are supplied, so the description must carry the behavioral load. It usefully discloses the return payload, which reads as a read-only lookup, but says nothing about rate limits, result ordering, or empty-result behavior. Pagination exists but is only explained in the schema, not here.

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-loaded with the core action and followed by the return shape and a use case. No filler, though the third sentence borders on redundant with the first.

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 keyword search with a fully documented schema and no output schema, the description covers purpose, return fields, and use case. Missing only result ordering and empty-result handling, which are minor for this complexity.

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%, including the pagination cursor and the 1-100 limit bound, so the baseline of 3 applies. The description adds mild value by framing the query as a keyword search over subreddit metadata, though it does not clarify matching semantics (name vs. description).

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: "Find subreddits by keyword," and enumerates what comes back (name, title, description, subscriber count, URL). It is clearly distinct from search_users and get_community_details in substance, but never names those siblings explicitly, 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?

"Useful for discovering niche communities related to a topic" implies a discovery use case but gives no explicit when-to-use or when-not guidance. It does not tell the agent to prefer get_community_details once a name is known, nor when to use the generic search sibling instead.

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