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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds genuinely useful non-annotation behavior: 'Free, no browser session' — the call costs nothing and does not open or occupy a Cloud Browser — and it discloses the content shape it returns, which matters with 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?

Everything is front-loaded: contents first, then the timing directive, then scope/cost caveats. The middle clause is a dense comma list inside one long sentence, slightly run-on, but each element carries information an agent needs and nothing is filler.

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 takes on the burden of describing what comes back and does so by enumerating the sections of the guide. Timing, scope, catalog fallback, and cost are all covered; only the output format/pagination of the guide itself is left unspecified, which is minor for a static reference lookup.

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 coverage is 100% and both parameters carry descriptions, so the baseline is 3. The description adds real semantic value on top: an app outside Cotlet's catalog still yields the general method rather than failing, which tells the agent how to interpret the 'app' parameter for unknown values. It adds nothing about the 'task' parameter beyond what the schema already says.

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?

Specific resource with clear sibling differentiation.

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?

'Call it before the first browser step in an app' gives an explicit trigger point in the workflow, and 'Works for any web app; one outside Cotlet's catalog gets the general method' pre-empts the common failure case of a non-catalog app. It stops short of stating when NOT to call it (e.g., no need to re-fetch mid-session once the guide is in hand), so it is clear but not fully exhaustive.

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