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 behavioral disclosure. It simply says 'Executes tests' without mentioning side effects (e.g., building, generating result bundles), requirements (e.g., active project), or expected behaviors such as failure handling or long-running operations.

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, direct sentence that is perfectly concise and front-loaded. Every word adds value, making it a model of efficiency.

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?

Despite high schema coverage, the description lacks workflow context. It does not explain how it relates to sibling tools (e.g., that it is for Xcode projects, not SPM), nor does it mention the need for an active project or the absence of an output schema. For a tool with 7 optional parameters and no annotations, this minimal description is incomplete.

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 input schema has 100% coverage with detailed descriptions for all 7 parameters, so the description does not need to add parameter-level semantics. The baseline of 3 applies because the schema carries the heavy lifting, and the description adds no extra meaning.

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 function: 'Executes tests for the active Xcode project.' It uses a specific verb ('executes') and specifies the resource ('tests') and scope ('active Xcode project'), distinguishing it from sibling tools like test_spm_package which test Swift packages.

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?

No guidance is provided on when to use this tool versus alternatives. It does not mention that it is specific to Xcode projects or that test_spm_package is for Swift Package Manager projects, nor does it list any prerequisites or exclusions.

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