build_test

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

No annotations are provided, so the description carries the full behavioral burden, and it delivers almost nothing: no indication that test execution is long-running, whether a simulator must already be booted (a sibling `build_boot_sim` exists), how failures are reported, or whether artifacts/logs are produced. The only disclosed trait is the simulator environment.

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?

It is a single front-loaded phrase with zero filler, so there is no verbosity problem. But it is a fragment rather than a structured sentence, and its brevity comes at the cost of under-specification rather than economy.

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?

An output schema exists, so return values need not be explained, but for a tool that spawns a test run the description omits everything else an agent needs: simulator prerequisites, expected runtime, and the meaning of the required project/scheme arguments. Given no annotations and 0% param coverage, the description is well below sufficient.

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 0% for all three parameters with no annotations to compensate. The description never clarifies whether `project` is an .xcodeproj or .xcworkspace path or what form `scheme` takes; the phrase 'on the simulator' only loosely gestures at `device_name`. This is far short of compensating for the coverage gap.

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 states a specific command and environment: it runs `xcodebuild test` against a simulator. That implicitly separates it from `build_for_sim` (build only), `maestro_test` (different runner), and `build_archive`, even though no sibling is named explicitly. It is a clear verb+resource, just extremely terse.

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 when-to-use guidance at all: nothing says when to pick this over `maestro_test`, `build_for_sim`, or `cpp_build_all`, and no prerequisites (e.g. simulator boot, scheme/project format) are given. The single parenthetical is a runtime detail, not usage guidance.

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