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

Annotations already supply readOnlyHint/openWorldHint, so the description adds real value beyond them: a real Chrome where the user is signed in, tab preservation (open tab else new tab), and the return being the in-view elements/text with matching numbers. Missing session-lifecycle detail, e.g. what happens if a browser is already running.

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 action, then the sequencing rule, then the return contract. The Airalo action list is useful routing but reads as a trailing enumeration; otherwise little waste.

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?

Complete enough for a 2-param, annotation-rich launcher with no output schema: sequencing, signed-in context, tab behavior, and return shape are covered. Minor gap on the extent of the returned view (visible window only?) and prior-session handling.

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?

Coverage is 100%, so the schema does the heavy lifting and baseline is 3. The description adds meaning about `url` routing (site's open tab vs a new tab) that the schema format line does not convey, and it reiterates the app default ('Leave it out').

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: 'Starts the user's Cloud Browser ... and opens `url`'. 'Call it first' plus the Cloud Browser qualification distinguishes it from all the other cotlet_browser_* siblings that presuppose an already-open browser.

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?

Explicit sequencing rule ('Call it first') and a downstream contract ('Answers the page after it'). It also names where it applies ('In Airalo it serves these actions') and the app parameter guidance routes app-specific cases to cotlet_app_guide.

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