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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description does add genuine behavioral context beyond the annotations by disclosing that detection is non-exhaustive (false negatives are expected), which is exactly the kind of caveat structured fields cannot convey. However, it says nothing about what a hit looks like, whether matches are returned with positions or severity, or how the text is analyzed, leaving the mutation-free behavioral picture thin.

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?

A single front-loaded sentence with the verb first and the scope caveat second; every clause earns its place and there is no filler. It is on the terse side, but nothing is wasted and the limitation is not buried.

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 tool is simple (one required string parameter, no nesting, no output schema), so expectations are modest, and the caveat about non-comprehensive coverage is valuable. With no output schema, the description is the only place a return shape (matched phrases, boolean, severity) could be described, and it is not, leaving the agent guessing what comes back on a hit versus a clean input.

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 0% and there is a single required parameter "text" with no documentation at all in the schema. The description partially compensates by framing the input as containing "phrases" to be matched, implying free-form text rather than structured data. It still leaves open whether the whole prompt, a user message, or an arbitrary document is expected, and does not address size or encoding expectations.

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 names a specific verb ("Flag") and a specific resource ("common prompt-injection or data-exfiltration phrases"), so an agent can tell precisely what the tool does. It does not differentiate itself from any sibling (e.g., privi_log_redact, which plausibly touches similar text), so it falls short of a 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?

Usage is only implied: the caveat "without claiming comprehensive protection" hints this is a heuristic first-pass check, not authoritative screening, which is useful boundary information. There is no explicit statement of when to call it, when not to, or what alternative to use for stronger screening.

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