CDP MCP

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

No annotations are provided, so the description carries full burden. It states the action but lacks critical behavioral details: it doesn't specify if this requires prior setup (e.g., a connected browser via cdp_connect), what the execution context entails (e.g., sandboxing, permissions), potential side effects (e.g., page modifications), or error handling. This leaves significant gaps for a tool that executes arbitrary JavaScript.

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, efficient sentence with zero waste—it directly states the tool's purpose without fluff. It's appropriately sized and front-loaded, making it easy for an agent to parse quickly.

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 executing JavaScript in a browser context, no annotations, and no output schema, the description is incomplete. It misses key details like required setup (e.g., connection via cdp_connect), return values (e.g., script results or errors), and safety considerations, which are crucial for effective tool 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?

Schema description coverage is 100%, so the schema fully documents both parameters (script and frame_id). The description doesn't add any meaning beyond this, such as examples of valid JavaScript or when to use frame_id versus default context. Baseline 3 is appropriate as the schema handles 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 clearly states the action ('Execute') and target ('JavaScript in the page context'), providing a specific verb+resource combination. However, it doesn't explicitly differentiate from sibling tools like cdp_interact or cdp_frame_interact that might also involve JavaScript execution, so it lacks sibling differentiation for a perfect score.

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 offers no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing a connected page via cdp_connect), exclusions, or comparisons to siblings like cdp_interact for simpler interactions, leaving the agent without contextual usage cues.

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