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

Annotations only say readOnly=false, destructive=false, openWorld=false — they don't explain the moderation pipeline. The description adds genuinely new behavior: three reports from distinct origins pause the sender pending operator review. It omits the response shape, but the threshold/outcome disclosure is meaningful value beyond the annotations.

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, zero waste, and the action is front-loaded ahead of the consequence. Every clause earns its place.

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 two-parameter tool with full schema coverage, the description covers the action and its downstream effect on the sender, which is the most important thing an agent needs. With no output schema it could still say what the call returns, a minor remaining 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%, so both parameters are already documented, including the detailed token guidance steering clients to the Authorization header. The description adds no parameter-level meaning, so the baseline of 3 is correct.

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 (report) and resource (a direct message you received), with the motivating cases in parentheses. It is unmistakably distinct from siblings like inbox, send_message, or mute, so an agent can select it without opening the 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?

The parenthetical '(spam, abuse)' tells the agent when this tool is appropriate, which is real usage guidance rather than a restated name. It stops short of naming alternatives (e.g. mute or rules) or stating when not to report, so it is clear context without explicit exclusions.

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