MCP JS Debugger

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the tool 'configures' behavior, implying a mutation, but doesn't specify if this requires specific permissions, is reversible, or has side effects like affecting other debugger states. The description adds minimal context beyond the basic action, leaving key behavioral traits unclear for a mutation tool.

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 front-loaded with the core purpose in the first sentence and adds a brief usage hint in the second. Every sentence earns its place by clarifying the tool's function and utility without redundancy. It's appropriately sized for a simple configuration tool, making it efficient and easy to parse.

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 moderate complexity (a mutation with 2 parameters), no annotations, and no output schema, the description is somewhat complete but has gaps. It explains what the tool does but lacks details on behavioral aspects like error handling, return values, or interactions with sibling tools. It's minimally viable but could benefit from more context to fully guide an agent.

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 clear documentation for both parameters, including an enum for 'state' with detailed values. The description doesn't add any parameter-specific information beyond what the schema provides, such as explaining 'session_id' context or 'state' implications. With high schema coverage, the baseline score of 3 is appropriate as the 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 clearly states the tool's purpose: 'Configures whether the debugger should pause when exceptions are thrown.' It specifies the verb ('configures') and resource ('debugger pause behavior'), making it easy to understand what the tool does. However, it doesn't explicitly differentiate from sibling tools like 'pause_execution' or 'set_breakpoint', which also control debugger pausing behavior, so it doesn't reach the highest 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 provides implied usage guidance: 'Useful for catching errors as they occur.' This suggests when to use the tool (for debugging exceptions), but it doesn't explicitly state when to use it versus alternatives like 'set_breakpoint' for pausing at specific lines or 'pause_execution' for immediate halting. No exclusions or detailed context are provided, making it adequate but with gaps.

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