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

Beyond annotations, the description reveals the authorization scope (`certs:manage`), the exact HTTP endpoint, and that standard PassFast billing and rate limits apply. It also warns against inventing other paths. These are behavioral details not captured in annotations. It doesn't describe side effects or response, but the test nature plus destructiveness=false cover the main safety profile.

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?

Four short sentences, front-loaded with the purpose. The scope, endpoint mapping, and constraint are each useful and non-redundant. No filler.

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 one-parameter test tool, the description is mostly complete, but the absence of an output schema is not compensated for: the agent is told nothing about the response format or how to interpret success/failure. Also, prerequisites such as previously uploaded credentials are only implied by 'configured.'

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 covers the only parameter (`x_app_id`) with a full description, so the schema does the heavy lifting. The tool description adds nothing about parameters, which is acceptable given 100% schema coverage.

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 ('tests') and resource ('configured Google Wallet credentials'), and clarifies exactly what the operation does (attempts to authenticate with the Google Wallet API). The endpoint and operationId further pin it down and distinguish it from sibling test tools like testAppleCertificates.

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 context is implied: this is the tool to call to verify Google Wallet credentials. However, it does not explicitly contrast with alternatives such as testAppleCertificates or testWebhook, nor does it state when not to use it. The 'Do not invent other paths' line is a constraint, not usage guidance.

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