build_app

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

With no annotations at all, the description carries the full burden and does real work: it discloses the side effect (installation onto the device), the return value (bundle ID), and that signing relies on the project's own settings so no signing parameters are needed. It leaves out failure modes such as signing errors or build duration, which keeps it from a 5.

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?

Three short sentences, front-loaded with the verb and resource, then scope, then return value, then signing behavior. Nothing is repeated from the schema except a brief reinforcement of the install default.

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?

No output schema exists, and the description compensates by naming the returned bundle ID. Defaults and the single required parameter are covered via the schema. The remaining gap is the unexplained project-vs-workspace choice and no note on what a failed build returns.

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 83%, with the device fallback chain and the install default already documented in the schema. The description only echoes the install default and does not clarify the mutually exclusive project vs workspace parameters, which is the main ambiguity an agent faces here.

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?

States a specific verb and resource ('Build an Xcode project/workspace scheme') and adds two scope facts an agent needs: it installs by default and returns the bundle ID. It stops short of naming siblings, so the overlap with install_app is left for the agent to infer.

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 parenthetical '(by default) install it' implicitly signals that install_app is a narrower alternative, and the device parameter's schema description documents the selection fallback chain. However, there is no explicit when-to-use/when-not guidance or statement of prerequisites such as needing a configured scheme.

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