debug_stack_trace

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

The description discloses that frames exist only while stopped at a breakpoint or runtime error, and explains the return format. This adds value beyond the readOnlyHint annotation (which indicates a safe read operation) by clarifying the conditions under which data is available.

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 concise with three sentences: purpose, return format, and empty list explanation. Every sentence provides value, and the key information is front-loaded.

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 absence of an output schema, the description adequately explains the return values (function name, file, zero-based line, reason) and handles the edge case of empty frames. It is complete enough for an agent to understand the tool's behavior.

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 schema already describes the single parameter (thread_id) as an integer with default 1. The description does not add additional meaning beyond what the schema provides, so a baseline score of 3 is appropriate.

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: 'Get the call stack where execution is currently paused.' This is a specific verb+resource combination that distinguishes it from sibling tools like debug_pause or debug_continue.

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 explains that an empty frame list means execution is not paused, providing context for when the tool is useful. It implicitly advises to use this tool only when paused, though it does not explicitly list alternative tools or when not to use.

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