reddit_get_subreddit_rules

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

Beyond the readOnlyHint annotation, the description adds valuable behavioral details: the server cannot perform any Reddit actions, results are cached locally, `self_promotion_restricted: null` means UNKNOWN rather than permission, and ambiguous rules should be surfaced. This goes well beyond what the annotations alone provide.

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?

The main purpose is front-loaded and clearly stated, but the description includes a long policy paragraph about product promotion and thread ranking that is not directly tied to fetching subreddit rules. Some statements also repeat what the annotations already convey, making the description somewhat heavier than necessary.

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 simple one-parameter schema, the presence of an output schema, and the annotations, the description is largely complete. It explains caching, read-only constraints, and ambiguity handling. It would be fully complete if it specified the expected subreddit argument format or named sibling alternatives.

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 no description for the `subreddit` parameter, and schema description coverage is 0%. The description only refers to 'a subreddit's rules' and does not explain expected format, casing, or whether the value includes 'r/'. It adds little semantic value beyond the parameter name and title.

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 states a specific action and resource: 'Fetch a subreddit's rules and a conservative reading of its self-promotion stance.' This clearly distinguishes it from sibling tools like reddit_search_posts or reddit_get_thread, which serve different purposes.

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 gives context about the read-only server and instructs the agent to respect subreddit rules and surface ambiguity, which implies when the tool should be used. However, it never explicitly states when to prefer this tool over alternatives or when not to use it.

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