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

Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds value beyond that: it discloses what data is returned (status, scheduledAt/publishedAt, provider URL once live, error message) and that the call is free — no credit spend. It omits any auth or error-handling behavior, keeping it short of a 5.

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?

One sentence, front-loaded with the verb and resource, with the return payload and cost note packed into a tight em-dash clause. No filler or redundancy.

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 does so by naming the key fields an agent would need. Combined with annotations covering safety and the explicit 'Free' cost signal, an agent has enough to call it correctly; only pagination/auth edge cases are unaddressed, which is minor for a single-record fetch.

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 100% and there is a single parameter (postId, a social post UUID), so the schema fully documents the input. The description adds only 'by id', which conveys no extra syntax or format detail beyond the schema. Baseline 3 is appropriate.

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 (Fetch) plus resource (one connected-account post) and narrows scope to lookup by id, which separates it from list_social_posts. It enumerates the returned fields, so the agent knows exactly what it gets. It does not explicitly name the sibling to use for listing, so it falls just short of a 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?

Usage is implied by 'by id' — the agent infers this is for retrieving a known post rather than discovering posts. There is no explicit when/when-not statement or pointer to list_social_posts for enumeration. The trailing 'Free' hints at a cost consideration but is not framed as guidance.

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