check_password_breach

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

With no annotations, the description carries the full burden and exceeds it. It discloses k-anonymity, that no plaintext is sent, the price, and the exact behavior with and without the _payment parameter. This is comprehensive.

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 sentences, front-loaded with the key action, followed by essential details. Every sentence contributes meaning without redundancy.

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?

The description covers all relevant aspects: purpose, usage conditions, parameter behavior, and response scenarios (with/without payment). No gaps remain for a tool with two parameters and no 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 coverage is 100%, so baseline is 3. The description adds value by explaining the role of _payment (402 behavior) and the k-anonymity context for sha1_prefix, going beyond the schema's pattern and examples.

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 clearly states the tool checks a password hash prefix against the HIBP breach corpus using k-anonymity. It uses a specific verb ('check') and resource, and distinguishes itself from siblings by highlighting the privacy-preserving approach and payment model.

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?

The description explains when to use the tool (to check a password breach without sending plaintext) and the payment requirement. It does not explicitly list when not to use it or provide alternatives, but the context of k-anonymity and pricing is clear.

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