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

With no annotations, the description carries the full disclosure burden and does well: it states the $0.10 USDC charge on Base via x402 (a real cost barrier), that the call is keyless, and that passwords are checked via k-anonymity SHA-1 prefix and emails sent to named third parties. It stops short of describing what a result looks like or what happens on lookup failure.

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 compact sentences with no filler; the functional purpose is front-loaded and the cost/mechanism follow it. Every clause (providers, optional password, payment rail) carries information an agent needs.

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 paid, 2-parameter tool with no annotations and no output schema, the description covers cost, inputs, and privacy mechanism but says nothing about the shape or content of the response, which matters when the caller is spending USDC. It is adequate but leaves a meaningful gap.

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 and the baseline is 3. The description adds the source services behind the email lookup and reinforces the SHA-1 prefix mechanism for the password, but contributes no new constraints, formats, or validation rules.

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 and resource ('email breach intelligence check') and even identifies the underlying data providers (XposedOrNot, HIBP), plus the optional password lookup. It is clear what the tool does, though it does not explicitly contrast itself with nearby siblings like threat-scan or full-privacy-sweep.

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?

There is no explicit when-to-use guidance, no conditions for choosing this over threat-scan/full-privacy-sweep, and no prerequisites stated beyond an implied paid call. The word 'optional' on the password parameter is the only usage signal, and it lives in the schema rather than the description.

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