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

With no annotations present, the description carries the full behavioral burden and does so well: it discloses the external API dependency, the k-anonymity data-leak surface (only the first 5 SHA-1 characters leave the server), that nothing is stored, and the per-call credit cost. These are exactly the traits an agent cannot infer from schema or 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?

Four tight sentences, front-loaded with the primary action, followed by mechanism, privacy, parameter alternative, and cost. No filler; every sentence carries a distinct piece of information.

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 ideally sketch the return values (entropy estimate, breach hit count), which it only implies. Given the simple 2-parameter surface and the strong privacy/cost disclosure, it is still nearly 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 description coverage is 0%, so the description must compensate, and it partially does by explaining that a SHA-1 hash may be supplied instead of the raw password. However, it does not clarify that both parameters are optional, nor what happens if neither (or both) are supplied, leaving a real gap for a 2-param tool.

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 a specific verb+resource pair ('Estimate password entropy and check whether it appears in known data breaches') and the exact backing API (Have I Been Pwned range API). This clearly separates it from ambiguous siblings such as hash_identify, email_check, and phishing_url_check.

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 by the purpose but there is no explicit when-to-use statement, no exclusions, and no routing to sibling tools (e.g. hash_identify for identifying an unknown hash vs. checking a known password). The cost note is the only decision-aiding guidance, so it sits at minimum-viable.

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