debug_step

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

No annotations are present, so the description bears full responsibility. It thoroughly discloses behavioral traits: blocking vs. fire-and-forget for each direction, approximate timing (~ms), and the exact return shapes. This is comprehensive and leaves no ambiguity.

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 well-structured with a clear header and bullet-like entries for each direction. It is concise but informative; every sentence adds value. Minor redundancy could be trimmed, but overall it is efficient.

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 complexity (4 parameters, no output schema), the description covers the main behaviors and return formats. However, it does not clarify the exact impact of the optional boolean parameters when set to false (e.g., whether the stack field is omitted or just empty). This slight omission prevents a perfect score.

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 coverage is 100%, providing a baseline of 3. The description adds significant value by explaining how each direction affects return values and behavior, and that optional booleans are ignored for 'continue'. This goes beyond the schema's field descriptions.

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 ('Advance the target') and immediately enumerates the four possible directions with specific behavioral details. The inclusion of return shapes for each direction distinguishes it from sibling debug tools.

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 implicit context for when to use this tool (when stepping through code) and explicitly notes that 'continue' requires polling debug_state for the next stop. However, it does not directly compare to alternative tools like debug_state or debug_eval, nor does it state when NOT to use this tool.

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