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

Annotations already declare readOnly=true, idempotent=true, destructive=false, and closed-world, so the safety profile is fully covered structurally. The description adds only the endpoint path (POST /v1/regex-safety); it does not mention size limits on patterns or test_strings, execution cost of backtracking tests, or whether anything is logged, which is the kind of context annotations cannot carry.

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 core capability first and the endpoint trailing in parentheses; no filler. Slightly over-packed with three verbs, but every clause conveys something.

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 should say what the scan returns — a vulnerability verdict, severity, explanation text, match results — and it does not. Requiredness of pattern and flags is left entirely to the schema, and the agent cannot anticipate the response shape.

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 baseline of 3 applies; the schema itself is generic placeholder text, but the description only loosely gestures at test_strings via 'test matches' and says nothing about flags syntax or pattern format. It neither compensates for nor degrades the schema.

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 resource and verb set: auditing regular expressions for O(2^n) ReDoS backtracking, explaining patterns, and testing matches. The resource is distinct from every listed sibling, but the description offers no explicit sibling differentiation and bundles three capabilities without saying whether they are returned together or selected by parameters.

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 by the capability list; there is no statement of when to reach for this versus e.g. prompt_guard or secret_scanner, no prerequisites, and no note on what a safe versus unsafe result means for the caller. An agent can infer 'audit a regex before deploying it' but nothing is stated.

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