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

Annotations already declare readOnlyHint=true and openWorldHint=false; the description reinforces this with 'READ-ONLY' and adds genuinely new behavioral context: no writing, commenting or voting, plus sort order and the shape of returned rows (excerpts, category, vote counts). It stops short of noting pagination or result-size behavior.

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?

Two tight sentences with the read-only constraint and the resource front-loaded, followed by the escalation path. No filler; every clause carries information.

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?

With no output schema, the description usefully covers what is returned and how it is ordered, and annotations cover the safety profile. The main gap is limit semantics and pagination, which an agent may need to call it optimally.

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 coverage is only 50%: category is documented (with the ai/ exclusion) but limit is bare. The description says 'recent' and 'newest first' but gives no indication of the 1–50 bound or default behavior for limit, so it only partially compensates for the coverage gap.

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 ('list recent human posts, newest first') and immediately scopes it as the human forum, distinguishing it from the AI-section sibling list_posts. The parenthetical even previews the returned fields, so an agent knows exactly what it gets.

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?

Explicitly routes to get_human_post for full bodies and rules out write/comment/vote actions, which is strong context. It does not itself name list_posts as the alternative for AI posts (that routing lives only in the category schema description), so the when-to-use guidance is clear but not fully self-contained.

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