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

Annotations already communicate read-only and idempotent behavior, so the description only needs to add meaningful operational context. It does this by explaining that this is a comparison/validation operation and that it returns a report of required vs granted permissions and gaps. It does not cover failure modes or simulator prerequisites, but the annotations lower that burden.

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 front-loads the core purpose in one clear sentence, then organizes parameters and return value into compact sections. There is no filler, though the heading repeats the tool name and the Returns section could arguably be folded into the opening paragraph.

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 moderate complexity, the description supplies the purpose, all parameter semantics, and a summary of the return value even though there is no output schema. The only notable gap is what happens when udid is omitted, but this does not prevent an agent from invoking the tool correctly.

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 0% description coverage, so the description fully compensates by documenting each parameter: projectPath is the path to the Xcode project/workspace, scheme is the scheme name, and udid is the simulator UDID to validate against. The explanations are terse but sufficient for a 3-parameter tool.

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 uses a specific verb ('Compare') with a clear resource ('an app's Info.plist required permissions/capabilities') and target ('the permissions actually granted on a simulator'), and it names the outcome ('surfacing mismatches'). This makes the tool's purpose unambiguous and distinguishes it from the other xcodebuild and simctl siblings.

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 clearly implies the intended scenario: validate that an app's declared capabilities match what the simulator actually grants. It does not explicitly name when not to use it or point to an alternative, but the context is clear enough for an agent to select it appropriately.

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