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

Annotations already cover read-only/idempotent/non-destructive behavior, and the description adds meaningful policy context: it only produces a first-party handoff, must not collect sensitive data, and must not conflate a purchase with funding. No contradiction with 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?

One dense sentence that front-loads the trigger condition and then states hard constraints. No filler or repetition of schema/annotation information.

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 3-parameter tool with an output schema and safety annotations, the description covers trigger, scope, authorization requirement, and misuse prevention. An agent has what it needs to use the tool correctly.

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?

With 67% schema coverage and no explicit parameter explanations in the description, the required bounty_contract and amount_base_units rely on their names and the schema pattern/min-max. The description's Base USDC context supports amount_base_units, but it does not add detail about units or the contract's role.

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?

The description names a specific action (prepare a first-party MoonPay handoff) and a specific trigger (person funding one canonical Base bounty needs Base USDC), which clearly separates it from sibling prepare_bounty_action/post tools. It also uses 'only' to delimit the tool's scope.

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?

It gives an explicit when-to-use condition ('Use this when a person... needs Base USDC') and explicit prohibitions ('never request card data... never treat a MoonPay purchase as bounty funding... require a separate canonical funding authorization'). This tells an agent when and when not to invoke the tool.

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