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

No annotations are provided, so the description carries the full burden. It usefully discloses the return shape and a privacy guarantee (the value is not stored), but says nothing about the estimation method, whether it is a local vs network computation, or any rate/permission considerations.

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?

Three tight sentences with the purpose, input, output, and a usage hint front-loaded. No filler, though the "Input: `password`" fragment barely earns its place.

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?

For a simple two-param tool with no output schema, the description does cover the return values, which is the main gap it needs to fill. However, the undocumented `locale` parameter and the silent estimation methodology leave it only partially complete.

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 0%, so the description must compensate. It names the `password` parameter but adds no semantics beyond the schema's type, and omits the `locale` enum parameter entirely, leaving one of two parameters undocumented in both places.

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 ('Estimate a password strength') and enumerates the return values (0–4 score, label, entropy bits). This is clearly distinguishable from the utility siblings, none of which touch password analysis, though it does not explicitly name any sibling it differs from.

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?

"Use to advise users" implies a usage context but gives no when-not conditions, prerequisites, or alternatives. It is adequate as a hint but not a real routing rule.

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