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

Annotations already declare readOnly, idempotent, non-destructive and open-world, and the description adds traits the annotations cannot carry: a 10-25 second runtime, a per-client daily quota on the free plan, and the fact that detail/fixes are gated behind an email via unlock_report. Those are exactly the operational facts an agent needs before deciding to call.

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?

Front-loaded with what the tool does and returns, then latency, then input constraint, then quota. Every sentence carries information an agent would otherwise have to guess; nothing is repeated from the schema or annotations.

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?

No output schema exists, so the description enumerates the return payload itself, including the 48-check status list and shareable link. Combined with the latency, quota and unlock path, an agent has everything needed to decide and to explain the outcome to a user.

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 schema fully documents the single url parameter, and the description adds real meaning beyond it by excluding deep links and steering toward domain or homepage form. With only one parameter and 100% schema coverage the ceiling is limited, but the added constraint is genuinely useful.

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 (runs an audit) and resource (public website), names the vendor and what the result contains (score out of 100, grade, platform, category scores, top three issues, 48 checks, report link). This is clearly distinguishable from explain_fix, get_report and list_checks, which operate on an already-produced report.

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?

Gives explicit input guidance ('Use the domain or homepage URL, not a deep link') and routes the user to unlock_report when per-check detail or fixes are needed. It also states the free-plan quota. It stops short of stating when to prefer get_report or list_checks instead, so it is clear context rather than full when/when-not coverage.

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