ios.build_app

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

With no annotations, the description carries the full behavioral burden. It includes a '[device mutation][risk:device]' tag that flags risk potential, which is useful, but it does not explain what mutation might occur, whether it requires a booted simulator, or if it overwrites previous artifacts. The tag is a partial disclosure, not a complete one.

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 sentence with the risk tag front-loaded. It is concise and free of fluff, but the extreme brevity leaves out critical information that could be added without losing conciseness.

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 complex tool with 9 parameters, no output schema, and no annotations, this one-line description is severely incomplete. It does not explain what the MCP artifact contains, how the build result is returned, or what the device mutation risk concretely entails. An agent would have to guess most details about invocation and side effects.

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% across 9 parameters, including a nested buildSettings object. The description merely mentions xcodebuild, giving no semantic context for scheme, project, workspace, destination, configuration, or xcodebuildArgs. It fails entirely to compensate for the missing schema descriptions.

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 a specific verb (Build), a specific resource (iOS simulator app), and the method (xcodebuild), which distinguishes it from Android build tools and iOS install/launch tools. It does not explicitly name a sibling to differentiate from, but the platform and simulator scope are evident.

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 description implies usage when an iOS simulator build is needed, but provides no explicit guidance on when to use it vs alternatives like ios.install_app or build.build_debug_apk, and no prerequisites are mentioned. This is implied usage rather than clear direction.

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