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

Beyond the annotations, the description discloses that this is a real Chrome session where the user is already signed in, that existing user tabs are preserved, and what the tool returns (elements and text in view with matching element numbers). It also implicitly explains the idempotentHint=false by noting the URL may land in an existing tab or spawn a new one; a rate/timeout note would be the remaining gap.

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 short and front-loads the action and the 'Call it first' directive, with no wasted clauses. The trailing sentence enumerating Workever actions is somewhat tangential but does orient the agent to the tool's usage context.

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 still explains what comes back after the page loads, and with zero required parameters and full schema coverage the invocation surface is fully covered. Nothing an agent needs to open the browser correctly 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%, so both `app` and `url` are already documented in the schema, including the careful 'leave it out' guidance for `app`. The description adds only marginal parameter meaning (the URL's destination tab), so the baseline 3 is appropriate.

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?

The description uses a clear verb+resource: it starts the user's Cloud Browser (a real, signed-in Chrome) and opens the given `url`. It also implicitly separates itself from cotlet_browser_navigate by telling the agent to 'Call it first', making the session-start role distinguishable, though it never names the sibling explicitly.

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?

Usage is framed strongly with 'Call it first', establishing the correct ordering relative to the other browser tools. It also explains tab-routing behavior (existing site tab, else new tab), but offers no explicit exclusion or named alternative such as cotlet_browser_navigate for subsequent page moves.

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