browser_performance_trace

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

No annotations provided, so description must fully disclose behavior. It mentions output format, supported metrics, and error scenarios (browser not launched, duration impact). However, it does not state whether the tool is read-only, whether traces persist, or cleanup behavior.

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?

Description includes both English and Chinese sections, causing redundancy. The English part is concise (2 sentences), but the Chinese section repeats and adds details. Could be streamlined without losing clarity.

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?

Tool has 5 optional parameters, no output schema, no nested objects. Description covers purpose, usage, parameters, output structure, and example. Provides enough context for an agent to understand the tool's function and expected results.

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% with clear descriptions. The description adds minor context (e.g., using current page if URL omitted) but largely repeats schema info. No new meaning beyond what schema already provides.

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?

Clearly states the tool records a complete performance trace and outputs HAR plus structured data. The verb 'Record' and resource 'performance trace' are specific. However, it doesn't differentiate from sibling tools like browser_performance or browser_har_export, which may overlap in purpose.

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?

Explicitly lists use cases in the Chinese section (e.g., deep performance analysis, HAR file forensics). Provides error conditions and an example. However, it doesn't mention when not to use this tool versus alternatives like browser_lighthouse_audit or browser_network_detail.

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