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

Annotations already declare readOnly, idempotent and non-destructive, so the safety bar is met structurally. The description adds genuinely useful behavior beyond them: returned values are REDACTED, the result is a signed object, and the call costs $0.5 USDC — a pricing signal no annotation conveys.

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 short sentences with the core purpose front-loaded. The clause 'for secret exposure, not agent security scan' is redundant restatement of the preceding sibling comparison and slightly garbles the routing guidance.

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, full annotation coverage, and 100% param coverage, the description only needs to add routing, redaction and cost context — which it does. It omits file-type or size limits for the untyped 'files' array, a minor gap given the output schema.

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 both parameters are already documented, making 3 the baseline. The phrase 'in text and files' mirrors the two params but adds no format, size or content-type detail beyond 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 verb and resource: 'Detect exposed credentials in text and files'. It also distinguishes itself from the closest sibling, run_agent_security_scan, so an agent can route between the two without opening either schema.

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?

Explicitly names the alternative ('use it rather than run_agent_security_scan for secret exposure') and the condition that selects this tool. It stops short of excluding related tools like scan_prompt_injection or redact_pii, which an agent scanning a noisy sibling list might also consider.

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