trace_start

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

Annotations already indicate a state-changing operation (readOnlyHint false, openWorldHint true). The description adds the useful follow-up command but does not disclose additional side effects such as resource usage, the need to stop the trace, or performance impact.

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 a single concise sentence that front-loads the purpose and includes a practical follow-up command. No unnecessary words.

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?

The description is adequate for a simple start action with one optional parameter, but it omits any guidance on the screenshots parameter and does not mention pairing with trace_stop, which is important for correct usage.

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% and the description does not mention the 'screenshots' parameter at all. The agent is left to infer its meaning from the name and default, which is insufficient given the low coverage.

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 states a specific verb (Start) and resource (Playwright trace), and the follow-up command 'open it later' clarifies the action. It implicitly distinguishes from the sibling trace_stop by focusing on the start action.

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 implies the tool is for starting a trace but does not explicitly state when to use it versus alternatives (like trace_stop) or any conditions/exclusions. It lacks clear guidance on the appropriate context.

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