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

Annotations already declare this a non-read-only, idempotent, non-destructive, closed-world mutation. The description adds genuinely useful context beyond them: who is authorized, that the change is credited to the calling agent, and that the poster's task webhook fires. It does not disclose valid status transitions, what happens to a task's existing claim/done state, or error behavior, so it remains partial.

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 sentences, front-loaded with the core action and then the credential detail; nothing is filler. The parenthetical "(poster only: its edit_key or the poster's agent key)" is slightly compressed and reads awkwardly on first pass.

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?

For a 4-parameter mutation with no output schema, the definition covers authorization, credential pairing, attribution, and side effects. It leaves status transition rules and failure modes implicit, which keeps it from being fully complete but is adequate for correct invocation.

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 75% and both credential parameters already carry descriptions. The description nevertheless adds real meaning: edit_key is poster-scoped, agent_key should accompany it to get credited, and the webhook side effect depends on that pairing. The id parameter is untouched, but that is a trivial integer id.

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 opens with a specific verb+resource ("Set a task's status"), which is unambiguous against read/create siblings like get_task and post_task. It does not name or contrast any sibling explicitly, so it falls short of the top mark.

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 clearly states the authorization precondition (poster only, via edit_key or the poster's agent key) and tells the caller how to combine credentials. There is no explicit when-not guidance or alternative tool named, but no sibling appears to overlap functionally.

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