Self-check for residual identifiers

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

readOnlyHint=true already signals safety, and the description adds valuable non-obvious context: the tool is deliberately non-authoritative ('not a guarantee') and returns only 'possible leftovers' rather than a definitive result. No contradiction with annotations.

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?

Three short sentences with no waste. The action and target are front-loaded, the reliability caveat is compact, and the return type is stated clearly.

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, read-only tool with no output schema, the description covers input, output shape ('list of possible leftovers'), and reliability expectations. Nothing essential is missing for correct 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?

The single 'text' parameter has 100% schema coverage, so the baseline is 3. The description adds extra meaning by clarifying what an identifier can look like, which helps the agent understand what input 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?

States a specific verb ('Scan') and exact resource ('already-redacted text'), and defines the target class with concrete examples (long numbers, emails, postcodes, URLs). It does not explicitly contrast with the sibling 'check_output', so it stays at 4 rather than 5.

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 modifier 'already-redacted text' and the phrase 'second pair of eyes' clearly indicate a post-redaction review pass, giving enough context for an agent to choose this tool. It does not enumerate exclusions or name an alternative tool.

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