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

Annotations already declare readOnlyHint and destructiveHint=false, and the description layers on genuinely useful behavior: findings are fully masked, there is no key/credit/wallet requirement, and existing source/input limits apply. These add real value beyond the structured hints, though the pattern families themselves are undisclosed.

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?

Front-loaded with the core capability followed by compact auth/pricing notes; three short sentences with little waste. The pricing statements are somewhat peripheral but still functional within a validation context.

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 an output schema present, return-format details are not the description's burden, and it does cover masking and no-auth. However it omits what the five pattern families are and what the input limits actually are, leaving meaningful gaps for a security-scanning tool.

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 coverage is 67%, with text/requestId/maxPriceMicroUsd partly documented in-schema (and the legacy fields marked ignored). The description only alludes to 'source and input limits' without defining the text parameter or naming the five credential families, so baseline 3 is warranted.

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 (Detect) and resource (credential patterns, five families) with the added qualifier that findings are fully masked. This distinguishes it reasonably from security_secret_redact, but it never names the sibling or explains the detect-vs-redact division explicitly.

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?

It supplies pricing/auth context (FREE during validation, no key/credits/wallet) but gives no when-to-use guidance and no routing to alternatives such as security_secret_redact. An agent still has to infer which secret tool to pick.

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