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

The description adds meaningful context beyond the readOnlyHint annotation: cost (1 credit), account requirement (Prowlo), platform-specific parameter handling (channel ignored for HN, time only for top/controversial), and a read-only note. No contradiction with annotations.

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 description is compact and front-loaded with the core action ('List posts/stories'), then efficiently organizes platform specifics in a semicolon-separated list. There is no filler or 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?

It covers platform requirements, defaults, limits, cost, and auth. However, it omits any mention of pagination, continuation tokens, or response structure, which would be helpful for a list endpoint.

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?

Even though schema coverage is 100%, the description adds crucial semantics: channel becomes conditionally required for reddit, limit caps are platform-specific (≤20 for reddit vs ≤30 for HN), time only applies to certain sorts, and sort defaults are clarified. This goes far beyond the schema's property descriptions.

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 identifies the action ('List posts/stories') and specifies both platforms with distinct behavior. It distinguishes from siblings like social_get_post by focusing on listing, and from social_search by straightforward feed retrieval.

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?

It provides explicit per-platform instructions: channel is required for reddit, sort defaults for hackernews, and platform-specific limits. However, it does not explicitly name alternative tools or state when not to use this tool, so it lacks explicit exclusion/alternative guidance.

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