Check output for leaked identifiers

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

Adds meaningful behavior beyond the readOnly annotation: tolerant matching for spacing, dashes and case, re-tokenisation of found values, and an explicit guarantee that raw values are never returned. This lets an agent predict both safety and output shape.

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 dense sentences carry all critical information, with the operation and key guarantee front-loaded. No filler or repetition of schema.

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?

With no output schema, the description compensates by specifying the returned elements: leaked token categories (never raw values), sanitised text, and a self-check. It also states matching tolerance and detection scope, so an agent has enough to call and interpret the result.

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 describes both parameters fully (text and session_id, with session_id explicitly linked to protect), so baseline 3 applies. The description adds no parameter-specific detail, which is acceptable at 100% 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 ('Scan ... and re-tokenise') with a clear resource (generated text and protected session values). The restriction to 'verbatim reappearance only' distinguishes it from sibling tools like self_check and redact even though no sibling is named.

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 scope line makes the intended use clear: run this after generation to catch verbatim leaks from a protected session, not paraphrases or inferred identities. It provides a when-not condition ('paraphrases and inferred identities are not detected') but doesn't explicitly name an alternative tool for those cases.

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