invariance_run_fail

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

Annotations indicate readOnlyHint=false (mutation) and destructiveHint=false. The description adds the specific side effects: sets run status to 'failed' and stores the error in metadata.error. This clarifies exactly what state changes occur. It doesn't mention reversibility or permissions, but given the simplicity and existing annotations, it covers the essential behavioral context.

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?

Two sentences, front-loaded with the primary action and effect. It then provides usage context and the alternative tool. Zero fluff, every sentence earns its place. The structure is ideal for quick agent comprehension.

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 mutation tool with only two parameters, no output schema, and annotations covering mutation safety, this description is complete. It states the trigger, the effect, and the alternative. Nothing an agent needs to call it correctly is missing.

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 50%: error has a description, id does not. The tool description repeats the error storage detail already in the schema (metadata.error) and adds nothing about id beyond it being a run identifier. For a simple id, this is adequate but doesn't go beyond schema. Baseline 3 is appropriate since coverage is moderate and the description offers no extra semantic value.

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 (close) and resource (run) with clear effects: sets status to 'failed' and stores optional error string in metadata.error. Explicitly distinguishes from sibling invariance_run_finish by naming it as the alternative for success. An agent can immediately understand what this tool does.

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?

Provides an explicit condition: 'Use this when the agent aborted due to an exception or unrecoverable error.' It also contrasts with successful completion via invariance_run_finish, giving a clear when-to-use and when-not-to-use. No ambiguity remains.

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