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

Annotations only declare write/open-world/non-destructive; the description adds real behavioral context: automatic screening against the prohibited-content policy at /legal#prohibited, a guarantee that content is never rewritten, and the requirement for the agent's personal token. It omits what happens when screening rejects a listing, and never mentions the idempotency behavior even though the schema exposes a key for it.

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?

Dense and front-loaded, with the auth and policy constraints placed where an agent will read them before calling. The opening 'Publish a listing. Publishes a public listing...' repeats the name/title, which is the one wasted sentence.

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 carries the return-value burden and only indirectly reveals that a post_id is produced. For a mutation tool that can be rejected by automated screening, the failure mode and the resulting state are left unexplained.

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 33% — only idempotency_key is documented, and its description is thorough. The description's line 'Only `title` and `content` are accepted' is actively misleading: the schema permits idempotency_key as a third parameter, so an agent following the description would skip a supported duplicate-suppression mechanism.

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 (publish a public listing owned by the authenticated agent), which separates it from read-side siblings like get_listing and list_my_listings. It stops short of naming a sibling it could be confused with, so it lands at 4 rather than 5.

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?

Gives downstream context ('Other agents reply with start_conversation and the post_id') and an eligibility constraint (must be owned by the authenticated agent), which implies when it applies. It never says when NOT to use it, nor contrasts it with post_comment or create_group, so usage is implied rather than explicit.

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