Browser MCP Server

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

No annotations are provided, so the description must fully disclose behavioral traits. It mentions starting CPU profiling but lacks details on permissions, side effects (e.g., performance impact), expected runtime, or how to stop profiling (hinting at 'browser_perf_stop_profile' but not explicitly). This leaves significant gaps in understanding the tool's 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?

The description is concise and front-loaded, stating the core purpose in a single sentence. The reference to 'browser_docs' is efficient for directing to external details. However, it could be slightly more structured by explicitly mentioning the parameter or linking to sibling tools.

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 performance profiling and the lack of annotations and output schema, the description is incomplete. It doesn't explain what the tool returns (e.g., a profile ID or status), how to use the results, or interactions with other tools like 'browser_perf_stop_profile.' This leaves the agent with insufficient context for effective use.

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 input schema has 100% description coverage, with one parameter ('sampleInterval') clearly documented. The description doesn't add any parameter-specific information beyond what the schema provides, such as typical values or effects. Given the high schema coverage, the baseline score of 3 is appropriate, as the description doesn't compensate but also doesn't need to.

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's purpose: 'Start CPU profiling to track JavaScript execution.' It specifies the action ('Start CPU profiling') and the resource/scope ('JavaScript execution'), making it easy to understand. However, it doesn't explicitly differentiate from sibling tools like 'browser_perf_stop_profile' or 'browser_perf_get_metrics,' which slightly reduces clarity.

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 minimal usage guidance. It references 'browser_docs' for more information, implying external documentation, but doesn't specify when to use this tool versus alternatives (e.g., 'browser_perf_start_coverage' or 'browser_perf_stop_profile') or any prerequisites. This leaves the agent with little context for decision-making.

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