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

Goes well beyond the annotations by stating that it acts as the user on that site, that certain button categories are refused, that each started minute of the session costs credits, and that the session ends on close or 3 minutes after the last call. This is exactly the kind of side-effect, safety-gate and billing context annotations cannot convey, and it is consistent with destructiveHint=true and openWorldHint=true.

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 and the return value, with safety refusals and session economics after. Slightly dense — the credit and idle-timeout sentence is operational boilerplate likely repeated across the cotlet_browser_* family — but every sentence carries information.

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?

For a one-parameter mutation tool with full annotation coverage and no output schema, the description closes the remaining gaps: what it returns (URL and title), what it will refuse to do, and the session lifecycle/cost. Nothing an agent needs before invoking it 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?

Schema coverage is 100% and the single parameter is fully documented as 'The element's number in the element list of the current page.' The description repeats that phrasing and only hints that the list must be obtained elsewhere, so it adds little beyond the schema; 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 (clicks) and resource (an element of the current page, addressed by its number in the element list) and names the return value (URL and title after the click). The element-number mechanism implicitly separates it from cotlet_browser_press, cotlet_browser_type and cotlet_browser_select, which act through other mechanisms, so an agent can pick correctly without opening schemas.

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 clear context for use ('current page in the user's BookingKoala Cloud Browser') plus explicit exclusions: pay/buy buttons and buttons on account or sign-in pages are refused. It does not, however, explicitly route the agent to siblings for navigation (cotlet_browser_navigate) or keyboard input (cotlet_browser_press), leaving that inference to the agent.

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