ruyi_trace_start

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

With no annotations provided, the description carries full burden. It details buffer clearing on first call, preservation on repeated calls, omission of pre-launch events, and the true enabling of recording even after browser launch. This is rich behavioral context beyond what annotations could provide.

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 somewhat lengthy but every sentence adds necessary nuance about buffer behavior, startup coverage, and protocol scope. It is front-loaded with the core action and structured logically, earning its length.

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 complexity of trace-start behavior and no annotations, the description covers key behavioral aspects and mentions the startup alternative. However, it does not explicitly connect to ruyi_trace_stop or mention return values, leaving a minor gap in complete contextual guidance.

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?

The description adds no meaning for the two parameters. Schema coverage is 50% (only outputFile has a description), and the description does not compensate for the undocumented pageIdx. Although pageIdx may be inferable from context, the description itself provides no parameter semantics.

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 tool starts recording a structured BiDi trace from the current moment, using a specific verb and resource. It also distinguishes itself from other tools (e.g., ruyi_trace_stop, ruyi_trace_get_results) and from Firefox's DOMTrace, making the purpose 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 provides explicit guidance on when buffer is cleared vs. preserved, and when repeated calls occur. It directly names an alternative (use ruyi_new_page with traceEnabled:true) to capture startup events, fulfilling the 'when to use vs alternatives' criterion.

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