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

Annotations only declare the generic profile (not read-only, open-world, not idempotent, non-destructive). The description adds substantive behavior beyond that: the scan triggers an actual site visit, submission depends on capacity, reuse produces prior evidence with evidenceCapturedAt and a domainCooldownEndsAt window, and the caller must poll rather than wait for an inline result.

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?

Purpose and exclusions are front-loaded, and the polling instructions come last in the natural reading order. The reuse/cooldown sentence is dense with three field names in a row, slightly taxing, but every sentence carries operational 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?

With no output schema, the description carries the return-value burden and does so partially: it names scanId, pollAfterSeconds, reused, evidenceCapturedAt, and domainCooldownEndsAt, and explains the polling protocol. What is missing is what the eventual result contains or how to handle a capacity rejection, leaving a small but real gap for a scan tool.

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?

There is a single parameter at 100% schema coverage, and the schema description already spells out the URL format restrictions (no path, query, credentials, fragment). The description reinforces 'Only submit the homepage URL' and adds 'public', but contributes no syntax or format detail the schema lacks, so the baseline 3 applies.

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 and resource ('Creates a scan and visits the website') with the exact scope ('public website homepage for cookies and tracking observed before interaction'). It also names the sibling get_quickscan_result as the follow-up, so an agent can distinguish the two without opening either schema.

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?

Explicit when-to-use ('user asks to check a public website homepage... before interaction') plus a concrete exclusion list: private pages, legal verdicts, accept/reject testing, monitoring, bulk scans. It also routes the agent to the next step via get_quickscan_result, which is the strongest form of alternative-routing guidance.

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