observe_tool_error

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

With no annotations provided, the description carries the full burden. It discloses a key behavioral trait: the tool is a no-op for unknown callIds. However, it does not detail other behaviors such as whether it overwrites existing errors, idempotency, or authorization needs.

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 extremely concise with two short sentences. The first sentence captures the main action, and the second adds a critical edge case. No unnecessary information.

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 has 2 required parameters, no output schema, and no annotations, the description covers the basic purpose and one edge case. However, it lacks details about return values, error handling, or whether the error message is appended/overwritten, leaving some gaps in completeness.

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 0%, so the description must add meaning for the two required parameters (callId, errorMessage). The description does not explain what callId represents (e.g., a tool invocation ID) or any constraints on errorMessage format. The agent must infer from the tool's purpose.

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 action: 'Record failure with an error message.' It also specifies a critical edge case: 'No-op on unknown callId.' This distinctively separates it from sibling tools like observe_tool_start or observe_tool_complete.

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 implies usage for recording failures but does not explicitly state when to use this tool versus alternatives (e.g., observe_tool_cancel) or provide guidance on prerequisites or 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.