debug_pausePause an active Node.js debugging session to halt execution and capture the current state. Returns the existing snapshot if already paused.
Request Debugger.pause. Returns the current snapshot if already paused.
| Name | Required | Description | Default |
|---|---|---|---|
| sessionId | No | Session id from debug_launch/debug_attach. Required when more than one session is live. | |
| timeoutMs | No | Timeout in milliseconds. Default 30000 |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds some behavioral context beyond the annotations by noting the snapshot-return behavior when already paused and the action of requesting a pause. However, it does not disclose whether the tool waits for the pause to happen, what happens when the target is not already paused, or the role of timeoutMs in the waiting 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 two short sentences with no filler. The core purpose is front-loaded in the first sentence, and the second sentence adds a distinct behavioral detail that is not redundant with the schema or annotations.
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 simple tool with fully documented optional parameters, the description is minimally adequate. However, there is no output schema, and the description only specifies the return value in the already-paused case, leaving the non-paused behavior and waiting semantics implied. It also lacks routing guidance among the many debugger sibling tools.
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 already documents both sessionId and timeoutMs with clear descriptions, and schema coverage is 100%. The description adds no additional parameter-level meaning, so the baseline score of 3 applies.
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 states a specific action and resource: 'Request Debugger.pause.' It also adds a useful behavioral detail about returning the current snapshot if already paused. It does not explicitly differentiate from siblings like debug_wait_for_pause or debug_resume, so it misses the top 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 gives no explicit guidance about when to use this tool versus alternatives such as debug_wait_for_pause or debug_resume. The phrase 'if already paused' hints at a state condition but does not explain when an agent should choose this tool over its siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.