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

Annotations already cover read-only and idempotent behavior, so the description adds genuinely new context: the tool becomes useful only after posting, returns links once complete, and should not be polled. The anti-loop warning is a behavioral trait not expressible in the 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?

Two short sentences, front-loaded with the return semantics and closed with the usage constraint. No filler, no restatement of the name.

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 burden of telling the agent what comes back, and it does ('the links once it has'). What's missing is the intermediate state (what it reports while the post is still pending), but the core contract is covered.

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?

One required parameter with 100% schema description coverage, so the schema already explains that post_id comes from post_to_social. The description reinforces the origin but adds no format or syntax detail beyond it; baseline 3 applies.

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 check verb against a specific resource (a post from post_to_social) and says what it yields: whether the post went out plus the links. An agent can distinguish it from the sibling post_to_social, which publishes rather than reports.

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 says when to call it ('when the user asks') and, more importantly, when not to ('not on a loop'), which is real operational guidance. It doesn't enumerate alternative status-check siblings, but the reference to post_to_social grounds the workflow.

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