Steps a stopped debug thread over the next line, into a called function, or out of the current function so you can control execution flow during debugging.
Step the stopped thread over the next line, into a function, or out of the current function.
| Name | Required | Description | Default |
|---|---|---|---|
| kind | Yes | ||
| timeout | No | ||
| sessionId | Yes |
Changes observed during successful MCP inspections.
v0.2.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden and only partially delivers: it discloses the 'thread must be stopped' precondition. It says nothing about what happens after the step (does the thread stay paused?), what the 15-second timeout governs, or how a failure is surfaced.
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?
A single well-formed sentence with the modes front-loaded and zero filler. It is efficient, though the parallel structure ('over the next line, into a function, or out of the current function') could be tightened slightly.
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 three-parameter debugger control tool with no annotations and no output schema, the definition covers the core action but leaves the agent guessing about timeout behavior and what state the debugger returns to. Adequate to call it, incomplete for calling it confidently.
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%, so the description must compensate. It does explain the three enum values of kind in plain language (over a line, into a function, out of a function), which is the highest-value parameter here, but sessionId and timeout receive no explanation beyond their names and defaults.
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 verb (step) plus the resource (stopped thread) and enumerates the three modes, which maps directly onto the kind enum. It implicitly distinguishes itself from debug_continue by scoping to 'the next line' rather than resuming execution, but never names a sibling explicitly.
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 phrase 'the stopped thread' implies the debuggee must already be paused, giving an implicit precondition. There is no explicit guidance on when to prefer stepping over debug_continue, debug_stack inspection, or when to use each of the three modes.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.