coverage_start

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

With no annotations, the description bears the burden of behavioral disclosure. It mentions wrapping CDP methods but does not state whether re-invocation restarts tracking, if it is safe to call multiple times, or what side effects occur (e.g., clearing previous data). The behavioral context is minimal.

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 two concise sentences, front-loaded with the primary purpose, followed by implementation detail and usage guidance. Every word adds value, and there is no redundancy.

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?

Given the tool's simplicity (2 booleans, no required params, output schema exists), the description covers the essential workflow. It could mention behavior on repeated calls or whether prior coverage data is discarded, but overall it is sufficient for an agent to use correctly.

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 0%, but the two Boolean parameters (js, css) are self-explanatory from the tool name and description. The description adds no further detail about their meaning beyond indicating that they enable collection for respective types. Baseline score of 3 is appropriate given simplicity and context.

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 clearly states the action ('Start collecting') and the resource ('JS/CSS code coverage'). It also references underlying CDP methods, distinguishing it from sibling 'coverage_stop'. The tool's purpose is unambiguous.

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?

The description explicitly tells the user to call 'coverage_stop()' to retrieve the report, providing a clear usage pattern. While it doesn't exclude other uses, this is sufficient guidance for the paired workflow.

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