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

Annotations already cover readOnly/openWorld/idempotency, yet the description adds substantial context beyond them: the session costs credits per started minute, it ends on close or 3 minutes after the last call, and the user watches live. These cost and timeout behaviors are exactly what an agent needs before starting a paid, observable session.

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?

The description is front-loaded with what the tool is, then usage, return value, and cost/session terms. Each sentence carries useful content, though the "user watches every step live" remark is the least load-bearing.

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-param tool with no output schema, the description is complete: it names the return values (page URL and title), the session cost model, the timeout behavior, and the authentication state. An agent has everything needed to invoke it and anticipate the consequences.

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 description coverage is 100% and the single optional `url` parameter is fully documented in the schema. The description adds only the detail that it "opens `url` when given," implying optionality, which the schema already conveys (required: 0). Baseline 3 is appropriate when the schema does the heavy lifting.

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: it wakes the user's PeoplePerHour Cloud Browser, a real Chrome hosted on Cotlet and signed in as the user. That is a crisp identity. However, it doesn't distinguish this tool from the sibling cotlet_browser_navigate, which likely handles navigation within the same session, so a sibling-differentiation gap remains.

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?

"Use it for what the PeoplePerHour tools do not cover" gives a clear routing rule for when to reach for the browser instead of the API-style siblings. It does not, though, address when to use open versus navigate/click within the browser family, leaving that distinction to be inferred.

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