open_run

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

With no annotations, the description discloses key behaviors: the Engine creates the evaluator contract, measures baseline, refuses an unbounded budget, and locks the run. It also describes the return format and warns about budget parameters. It does not cover permissions or reversibility, but provides solid context beyond trivial description.

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 well-structured with a purpose line, usage condition, behavioral explanation, return format, and a mistake warning. It is slightly longer than minimal but every sentence contributes value, avoiding fluff.

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 purpose, when to use, key behaviors, return values, and a common mistake, making it moderately complete. However, with 8 parameters and zero schema descriptions, the lack of per-parameter explanations and absence of annotations leaves gaps in how to effectively invoke the tool, especially for non-budget parameters.

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% for 8 parameters. The description only mentions max_evals, wall_clock_s, and max_cost_usd in a warning, implying they are budget constraints and at least one must be set. Other parameters like goal_text, seed, target, workers, and evaluator_ref remain unexplained, so the description does not sufficiently compensate for the low schema coverage.

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 action ('open and lock') on a specific resource ('evolution run'), and adds the crucial condition 'when no existing run matches the work,' which distinguishes it from sibling tools like join_run that likely handle existing runs.

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 gives an explicit trigger condition ('Call this once when no existing run matches the work'), but does not explicitly name alternative tools or state when not to use it beyond this condition. The 'Mistake to avoid' note adds usage guidance for budget parameters.

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