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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the safety profile is covered; the description adds genuinely new behavior: a confirmation prompt where the client supports one, fallback to the token's scope otherwise, and the fact that the message becomes publicly visible. It does not mention whether posting a 'resolved' phase mutates incident state or any rate limits, which keeps it below 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?

Three short sentences, front-loaded with the core action and audience before the confirmation caveat. 'Not read-only' is largely redundant with the readOnlyHint annotation, a minor wasted clause, but nothing else is padding.

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 an output schema present and annotations covering mutability, the description supplies the missing pieces an agent needs: public visibility of the content, the confirmation/token-scope auth behavior, and the phase+message shape. It stops short of describing side effects on incident status or failure modes, which is a small residual gap.

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 the schema already documents the id, the full phase list with default, and Markdown formatting rules. The description only restates 'phase + message' without adding syntax or constraint detail, so it earns the baseline 3 for a schema that does the heavy lifting.

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 (post an update to an incident's status-page timeline) plus the fields it carries (phase + message). The incident focus cleanly separates it from the sibling post_maintenance_update, and the 'public, customer-facing' qualifier tells the agent this is outward-visible output, not an internal note.

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?

The description establishes the audience ('what your subscribers and status-page visitors see'), which implies when this tool is appropriate, but never states explicit when-to-use or when-not conditions versus siblings like publish_incident, resolve_incident, or post_maintenance_update. The agent must infer the routing decision.

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