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

Annotations already cover read-only, idempotent, non-destructive, closed-world behavior, and the description still adds real value: in-flight scan handling (returns a running status rather than stale data) and an explicit scope boundary that results are findings, not a legal compliance verdict. Those are behavioral traits an agent cannot infer from annotations or 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?

Front-loaded with the core action, then the in-progress caveat, then the scope disclaimer. The sentence 'The result reports what was found' is thin on its own but serves as the lead-in to the compliance disclaimer, so waste is minimal rather than zero.

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 an output schema present, return-value detail is unnecessary, and annotations carry the safety profile, so the description's remaining burden is scope and edge-case behavior, which it covers well (running scans, non-compliance semantics). Only a note on report freshness or size/coverage expectations is missing.

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, and the schema already documents it at 100% coverage, including the omit-for-default behavior. The description adds no further meaning about domainId, so the baseline of 3 for high-coverage schemas 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 ('Returns the latest cookie report for one of your CookiePal domains') and enumerates the payload ('each cookie's category, and says whether it came from a local scan'). It is clearly distinguishable from siblings like start_scan or upload_scan_report, which it references by name.

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 concrete conditional guidance: when a start_scan crawl is still running, the tool reports that state instead of returning an old report. That tells an agent the right post-start_scan timing. It stops short of explicitly stating when-not to use it or naming a preferred alternative (e.g., upload_scan_report for externally produced reports).

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