psa_cert_lookup

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

With no annotations, the description carries the full burden, and it does so thoroughly. It discloses that the record is public, that only one graded card is looked up, that the result includes this-cert-specific population figures, that out-of-scope cert divisions produce a not-found error, and that other PSA data types require a login.

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?

The description is front-loaded with the core purpose and scope, followed by a compact but complete field list and explicit limitations. Every sentence contributes useful selection or invocation information, with no wasted words.

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?

Even without an output schema, the description enumerates all return fields and clarifies error behavior and auth requirements. For a single-parameter look-up tool, everything an agent needs to select, invoke, and interpret the result is present.

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 the input schema already documents cert_number as a numeric PSA certification number. The description reinforces that the parameter refers to a trading-card department cert, but it does not add substantial format, validation, or syntax detail beyond what the schema provides.

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 opens with a specific verb and resource: 'Verify a PSA certification number' against 'PSA's own public Cert Verification record'. It enumerates the exact fields returned, which leaves no ambiguity about what the tool does, and distinguishes it from related PSA data endpoints by scoping it to the trading-card department.

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 clearly states the intended use case and gives explicit exclusions: certs from non-trading-card divisions return not-found, and full Population Report / Auction Prices Realized are unavailable through this endpoint. It stops short of naming a specific sibling tool to use instead, but the selection conditions are clear enough for an agent.

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