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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely non-structural context: the input is never stored or logged, plus the commercial/payment model (10 free calls/day, then $0.001/call via x402 or X-API-Key credits) and the serving host. A rate limit and auth path are exactly the operational facts an agent cannot get from annotations.

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?

The first sentence front-loads the analytical content an agent needs to select the tool; the privacy and pricing sentences follow as supporting detail. It is dense with no filler, though the payment/pricing clause is long enough to compete with the purpose statement for attention.

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?

An output schema exists, so return-value explanation is unnecessary, and the description covers the remaining gaps: privacy handling, quota, payment/auth mechanism and host. For a one-parameter, side-effect-free tool this is essentially complete, with only the absence of any accuracy or coverage caveats keeping it from a 5.

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 100% and the single parameter is fully described, so the baseline would be 3. The 'never stored or logged' guarantee adds decision-relevant meaning for this particular parameter, since it tells the agent the secret input is safe to pass despite the schema's own caution to use a look-alike pattern.

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 the concrete analyses performed: entropy, common-password lookup, pattern checks (sequences, years, 'Word123!'), crack-time estimates and feedback. That is far more specific than the title alone and tells an agent exactly what signal it gets back. It stops short of a clean verb-first statement and offers no differentiation from siblings, though none in the list overlap.

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 implied rather than stated: an agent infers it should call this when it needs to rate a password, and the schema note steers toward test patterns. There is no explicit when-to-use/when-not-to-use framing and no named alternative, but the tool's domain is narrow enough that little inference is required.

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