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

Annotations only give the safety profile (readOnlyHint=false, destructiveHint=true, openWorldHint=true); the description adds substantial context beyond them: ordered step approval, the auth requirement that the user must be a listed approver for the CURRENT step, the meaning of a forbidden error, and the exact resulting state transitions. This goes well past what the structured fields convey.

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 but front-loaded: purpose first, then precondition, then auth/error semantics, then outcome. Every sentence carries operational weight, though the 'approval_status pending (post status in_approval)' phrasing and the id precondition are mildly redundant with the schema.

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 mutating workflow tool with no output schema, the description covers everything needed to call it correctly: precondition, prerequisite read, authorization rules, failure interpretation, and post-condition state changes. Nothing material is missing.

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% with a single parameter whose schema description already states the 'pending' approval_status constraint, so the description's restatement of that constraint adds little. Baseline 3 is appropriate when the schema fully documents the parameter.

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 (approve) and resource (the current step of a post's approval workflow), and explicitly frames it as a step-wise action distinct from reject_post or publish_post. An agent can distinguish it from all siblings without opening a schema.

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?

Explicit preconditions ('Only works on a post with approval_status pending'), a prerequisite action ('check get_post first'), and error handling guidance ('a forbidden error means the user isn't an approver for this step yet — tell them who needs to approve instead, don't retry'). This is textbook when/when-not guidance.

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