invariance_eval_case_create_from_run

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

Annotations already communicate that this is a non-read-only, non-destructive operation, and the description adds that it copies the run's input/output as expected. It does not explain side effects such as how provenance is stored or whether the source run is left untouched, but the annotation coverage lowers the burden.

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 one well-structured, front-loaded sentence with no fluff. It states the action, source, destination, and captured content efficiently without repeating schema details.

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 two-parameter creation tool with no output schema, this is minimally adequate, but it does not describe the return value or what the agent should expect after invocation. An agent would need to infer response behavior from convention rather than from this definition.

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 documents `body` thoroughly, including required source_run_id, optional fields, and an example, but `suite_id` has no description. With 50% schema coverage, the tool description should compensate for that gap; it only partially does via the phrase 'in a suite'.

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 uses a specific verb ('Snapshot ... as a new eval case') and identifies both the source resource (existing production run) and the target (eval case in a suite). It also states what is captured, 'input + output as expected', which clearly distinguishes it from generic case-creation tools like invariance_eval_case_create.

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 phrase 'Snapshot an existing production run' gives clear context for when this tool is appropriate, and 'in a suite' clarifies the destination. It does not explicitly name alternatives or exclusion conditions, but the usage scenario is direct enough that an agent can choose it over generic eval case creation.

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