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

Annotations already declare destructiveHint=true and idempotentHint=true; the description adds the meaningful outcome that the post is 'cancelled and will not be published'. It does not state whether a rejection can be reversed (undo_change exists as a sibling) or what a repeat call does, which matters for an agent deciding whether to confirm with a user first.

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 action, no filler. Every clause carries information: shop scope, precondition, identifier source, and outcome.

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?

Covers purpose, precondition, and outcome fairly well for a one-parameter mutation. However, for a destructive, non-read-only tool with no output schema, it leaves out reversibility, post-rejection state, and any failure behavior, which the agent needs before firing an irreversible action.

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 sole parameter's schema description already says 'from pending_approvals'; the description only restates this. Baseline 3 is appropriate since the schema does the work.

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 ('Rejects one post'), scoped to 'this Xyla shop' and to posts 'waiting for approval'. The word 'one' implicitly contrasts with the batch sibling approve_posts, but that contrast is never made explicit.

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?

Clear precondition (post must be waiting for approval) and a clear pointer to where the ID comes from (pending_approvals). It does not name approve_posts as the opposite action or say what to do if the post has already been handled, so guidance stops just short of explicit alternatives.

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