chrome-devtools-mcp-mux

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

Annotations provide readOnlyHint=true, indicating this is a safe read operation. The description adds context by specifying it provides 'more detailed information' on insights from trace recordings, which aligns with the annotation. It does not disclose additional behavioral traits like rate limits, authentication needs, or data formats, but since annotations cover the safety profile, this is adequate.

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, well-structured sentence that efficiently conveys the tool's purpose without unnecessary details. It is front-loaded with the main action and context, making it easy to understand quickly. However, it could be slightly more concise by avoiding redundancy like 'of an insight set.'

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 complexity (performance analysis with trace recordings), the description is minimal but adequate. Annotations cover safety, and the schema fully documents parameters. However, without an output schema, the description does not explain what 'more detailed information' includes (e.g., data format, structure), leaving a gap in understanding the return values.

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 100%, with clear descriptions for both parameters (insightSetId and insightName). The description does not add meaning beyond the schema, such as explaining how insight sets are generated or what 'more detailed information' entails. Given the high schema coverage, the baseline score of 3 is appropriate.

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: 'Provides more detailed information on a specific Performance Insight of an insight set that was highlighted in the results of a trace recording.' It specifies the verb ('provides more detailed information') and resource ('Performance Insight of an insight set'), but does not explicitly differentiate it from sibling tools like 'performance_start_trace' or 'performance_stop_trace', which are related but serve different functions.

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 usage context by mentioning 'insight set that was highlighted in the results of a trace recording,' suggesting it should be used after trace results are available. However, it does not provide explicit guidance on when to use this tool versus alternatives (e.g., other performance-related tools) or any exclusions, leaving some ambiguity for the agent.

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