run_tests

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

With no annotations provided, the description carries the full burden of disclosing behavior. It only says 'executes tests', but does not mention potential side effects, whether it blocks, returns output, or how failures are reported. For a tool that runs arbitrary scripts, this lacks critical behavioral detail and could lead the agent to expect different outcomes than what actually occurs.

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 a single, concise sentence that states the core purpose immediately. There is no redundancy or filler; it efficiently conveys the essential 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's simplicity (one optional parameter, no output schema), the description is minimally adequate. However, it omits any mention of return values, test result reporting, or whether it requires a specific environment. For a tool that executes arbitrary code, this missing context could be significant, but given the low complexity, a score of 3 is reasonable. The agent might need additional info to call it correctly in a broader workflow.

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 covers the single parameter test_script with a clear description and example, so the schema alone is sufficient. The main description does not add any additional meaning about the parameter—it simply mentions 'custom runner' without elaborating on the parameter's format or constraints. Since schema coverage is 100%, the baseline 3 is appropriate.

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 verb 'Executes' and the resource 'tests', and it specifies the two execution modes: GUT or a custom runner. It is distinct from sibling tools like validate_script or run_scene, which focus on validation or running scenes. However, it does not elaborate on what 'tests' means in this context or how it differs from other test-related tools, so it stops short of a perfect 5.

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?

There is no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., a project must be open), nor does it suggest when to use GUT versus a custom runner. The description simply states the action without any contextual advice, leaving the agent to infer usage.

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