Advance debugging by stepping into the current function call, pausing at its first statement so you can inspect execution flow and variables.
Step into the current call. Waits briefly for the program to stop; if the step is still executing after ~5s, returns success with state "running" and pending:true — the session becomes "paused" when the step completes
| Name | Required | Description | Default |
|---|---|---|---|
| sessionId | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and does disclose key runtime behavior: it waits briefly, times out after ~5s, returns state 'running' with pending:true, and later flips the session to 'paused'. It omits error/permission cases and whether a paused session is required, so it is not fully complete.
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?
One dense sentence that front-loads the action, then the async/timeout semantics. No wasted words, though the em-dash clause packs several facts together and slightly hurts scannability.
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?
No output schema exists, so the description appropriately explains the return state ('running', pending:true) and the eventual 'paused' transition. What remains missing is prerequisite/error context, but for a one-parameter step tool this is largely sufficient.
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 0% for the single sessionId parameter, and the description never explains it. However, sessionId is self-evident from the debug-session sibling family, so the gap is minor rather than crippling.
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?
States a specific debugger verb ('Step into') plus the target ('the current call'), which is directly distinguishable from the sibling step_over and step_out tools. It is clear what the tool does, though it doesn't explicitly name those alternatives.
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?
Usage is only implied: the description assumes the agent knows step_into means descend into the called function. There is no explicit when-to-use vs step_over/step_out guidance, nor any stated prerequisite that a session must be paused.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.