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

With no annotations provided, the description carries the transparency burden and does well: it discloses that this is a destructive write to a sensitive credential vault, requires proof of npub ownership, is free, and does not affect other fields. It does not explicitly state irreversibility, but 'delete' plus the sensitive-vault warning is sufficient.

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 compact and front-loaded: the primary action appears in the first sentence, and each subsequent sentence adds a distinct fact (scope, cost, auth requirement). 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 destructive credential operation with no annotations, the description covers purpose, scope, cost, ownership proof, and risk. An output schema exists, so return-value details are not needed; the only minor omission is explicit guidance about alternatives or irreversibility, both reasonably inferable.

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 100%, so the schema already documents all three parameters thoroughly. The description's 'proof of npub ownership' maps to dpop_token but adds no parameter-level meaning beyond the schema's detailed event-format explanation.

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 states a specific action and resource: 'Remove a single patron credential field' and clarifies scope with 'Deletes one field from stored credentials without affecting other fields.' This clearly distinguishes the tool from sibling operations like roastify_update_patron_credential or roastify_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 provides clear context for use: when the goal is to remove one credential field while preserving others. It does not explicitly name alternatives or exclusions, but the 'patron credential' wording and single-field scope give an agent enough context to select it over related credential tools.

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