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

With no annotations, the description must carry the behavioral burden. It discloses two key traits: the tool is keyless (no auth required) and it returns breach metadata only, not affected individuals ('what happened, not who'). It omits rate limits and pagination details, but the core behavioral context is present.

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?

One compact sentence plus a clarifying parenthetical. The action, resource, and scope are front-loaded with no wasted words.

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 values need not be described. For a simple one-parameter read tool, the description covers purpose, query meaning, and key scope and access traits. Explicit read-only and rate-limit notes are absent, but 'Search' and 'metadata' imply safe read behavior.

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?

The single 'query' parameter has 0% schema description coverage, so the description must compensate. It adds meaningful semantics by specifying that the query may be a breach name or a domain. It does not clarify match behavior (exact vs fuzzy) or formatting, but it substantially improves on the bare schema.

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 states a specific verb and resource: 'Search public breach metadata by breach name or domain.' It also clarifies scope with 'what happened, not who,' so an agent can tell exactly what this tool returns. The sibling tools are unrelated utilities, so no sibling differentiation is required.

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 gives clear context for when to use the tool: looking up public breach metadata by name or domain. There are no alternative breach-related siblings, so no exclusions or alternatives need naming. It stops short of explicit when-not guidance but leaves no real ambiguity.

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