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

Annotations already convey readOnly, idempotent, and non-destructive behavior. The description adds important behavioral context beyond annotations: 'This tool never charges' and 'validates the exact ... request,' which clarify that no purchase is executed. This is meaningful additional transparency, though it does not cover authentication, rate limits, or failure behavior.

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 tight sentences that front-load the main purpose and add the critical 'never charges' caveat. Every sentence earns its place, with no filler or repetition.

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?

The tool has a complex nested request object and no output schema. The description mentions the high-level return values (MPP purchase route and protected recovery token) and that it validates the request, which helps an agent understand the flow. It does not spell out field semantics, but the schema covers those details, so the description is reasonably complete for selection and invocation.

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 description coverage is 0%, and the description does not explain any of the required request fields (client_order_id, installation_public_key_jwk, expected_package_sha256, schema). The phrase 'exact Verified Mode release request' gives minimal context, but the description must compensate for the low schema coverage 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?

The description uses a specific verb ('validates') and resource ('Verified Mode release request'), and clearly states the tool returns an MPP purchase route and recovery token. It is clear about what the tool does, but it does not explicitly differentiate it from its siblings, especially prepare_claim_audit_purchase, relying on the title/name for that distinction.

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 description provides clear context: this is a validation/preparation step for a Verified Mode release request and explicitly says it never charges, implying it is a non-payment preparation step. However, it does not name alternatives or state when not to use this tool, so it stops short of full 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.