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

Annotations already declare idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is mostly covered. The description adds one genuinely useful behavioral fact — that the contact becomes unsendable from that item — but says nothing about whether rejection is reversible, what errors occur, or what state the item ends in.

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 with the action front-loaded and the consequence immediately after. The 'APP:' prefix is unexplained noise, but nothing else is wasted.

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?

An output schema exists so return values need no explanation, but for a mutation tool with seven undocumented, all-optional parameters, the description leaves the core question — which identifiers are required to target an item — completely unanswered.

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?

Seven parameters with 0% schema description coverage and zero required fields, and the description explains none of them. An agent cannot tell whether 'id' or 'reviewId' identifies the item, or what the external*/idempotencyKey fields are for; the description had the highest obligation to compensate here and does not.

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 ('Rejects') and resource ('email review item'), and the second sentence clarifies the state consequence. It does not name the obvious counterpart, approve_review_item, so an agent must infer the pairing from the sibling list rather than the text.

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?

Usage is only implied: the tool clearly applies to a single review item and the counterpart approve_review_item exists in the sibling set, but the description never states when to choose rejection over editing (edit_review_item) or approval, nor any prerequisites.

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