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

With no annotations, the description carries the behavioral burden and does a solid job: it explains the ordering requirement, handling of retried/cascaded errors, accepted element shapes (string or object with error/retried/action), and even notes no token or LLM usage. It does not specify the return format, but the core behavior is well disclosed.

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 compact and front-loaded with the main purpose. Every sentence earns its place: the core goal, a clarifying example, accepted input shapes, and the cost/behavior note. No filler or redundant restatement of the tool name.

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?

The description covers the input requirements, core logic, and constraints for a single-parameter tool. The main gap is not describing the exact return value or output format, which would be more important if there were no output schema, but the task is simple enough that the intent is largely inferable.

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 errors parameter at 100% coverage, so the baseline is 3. The description adds meaningful semantics beyond the schema by specifying 'ordered list (oldest first)' and clarifying element variants, which improves an agent's ability to construct valid input.

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 verb and resource: 'find the TRUE root' from an ordered list of errors. It clarifies the intended behavior with a concrete example (429 retried causing a 401) and explicitly contrasts with 'the final symptom,' making it easy to distinguish from sibling diagnostic 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?

It clearly states when to use the tool: when you have an ordered list of errors from a run, oldest first. It also gives an exclusion by saying it finds the root rather than the final symptom, but it does not explicitly name alternative sibling tools or list conditions when not to use it.

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