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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description adds genuinely useful context beyond that: a privacy/security guarantee ('Never returns passwords') and a preview of what the response contains, which is valuable since there is no output schema.

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?

A single dense sentence that front-loads the verb and scope before enumerating outputs; every clause earns its place. Slightly list-heavy but not padded.

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 carries the return-value burden and does so well by enumerating breaches, exposure breakdowns, risk scoring, and paste exposure. The only missing piece is routing guidance against siblings, which is a usage rather than completeness 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% and there is a single well-documented 'email' parameter, so the schema carries the semantics. The description restates 'one email address' consistent with the schema but adds no format, validation, or edge-case detail. Baseline 3 is appropriate.

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 (get) and resource (breach analytics) scoped to 'one email address', and enumerates the return contents (breaches, dates, descriptions, industry/year exposure, risk scoring, paste exposure). This is clear and concrete, but it never distinguishes itself from the similarly-scoped sibling check_email_breaches, leaving an agent to guess which to pick.

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 implies a single-email scope but gives no explicit when-to-use guidance, no exclusions, and never names the alternative check_email_breaches (or any other sibling). The agent must infer selection from the name alone.

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