chrome-devtools-mcp-mux

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

Annotations provide readOnlyHint=false, correctly indicating this is a mutation tool. The description adds minimal behavioral context beyond this - it mentions 'selected page' implying a page must be selected first, but doesn't disclose important traits like whether changes persist, if multiple emulations can be combined, or what happens when parameters are omitted. No contradiction with annotations exists.

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 extremely concise - a single sentence with no wasted words. It's front-loaded with the core purpose, though that purpose is vague. There's no unnecessary elaboration or redundancy.

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?

For a complex mutation tool with 6 parameters and no output schema, the description is inadequate. It doesn't explain what 'emulation' means in practice, doesn't mention that parameters are optional (all 0 required), and provides no information about return values or side effects despite the tool's potential complexity.

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?

With 100% schema description coverage, the schema fully documents all 6 parameters with detailed descriptions and constraints. The description adds no parameter-specific information beyond the generic 'various features' mention, so it meets the baseline 3 score where schema does the heavy lifting.

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 'Emulates various features on the selected page' is vague and tautological - it essentially restates the tool name 'emulate' without specifying what features are emulated or how. It doesn't distinguish this tool from siblings like 'resize_page' or 'performance_start_trace' that also modify page behavior.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (needing a selected page), doesn't explain when emulation is appropriate versus using other tools, and offers no exclusion criteria or comparison to sibling tools.

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