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

No annotations are provided, so the description carries the full burden. It discloses that this is a write to a sensitive credential vault, requires ownership proof, is free, and does not affect other fields. This is solid behavioral transparency, though it omits details like error handling or idempotency.

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, each earning its place: the first states the purpose, the second adds scope, cost, and authentication requirements. Front-loaded and free of fluff.

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 description covers purpose, side-effect scope, cost, and a key prerequisite. The presence of an output schema covers return values. For a simple single-field delete, this is adequately complete, though it could mention irreversibility or what happens if the field does not exist.

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?

The input schema has 100% description coverage for all three parameters, so the description adds no additional parameter-level meaning. It indirectly references the dpop_token requirement but does not explain any parameter beyond what the schema already provides. Baseline 3 is appropriate.

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 'Remove a single patron credential field' – a specific verb and resource. It clarifies scope ('Deletes one field... without affecting other fields') and explicitly uses 'patron' to distinguish from sibling tools like delete_operator_credential.

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 implies when to use (removing a single field) and includes a prerequisite ('Proof of npub ownership is required'), but does not mention alternatives or exclusions. Sibling tools like delete_operator_credential and forget_credentials are not referenced, leaving the agent to infer the correct choice from the name alone.

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