iOS Simulator: Install

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

The description discloses the important overwrite behavior: installing over an existing copy replaces it and keeps its data. It also explains the misleading 'No such file or directory' failure mode for invalid builds, which is exactly the kind of context an agent needs to interpret errors correctly. This adds real value beyond the annotations.

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?

Two sentences deliver the core instruction, the key input constraint, the failure mode, and the overwrite behavior with no filler. The most important constraint is front-loaded, and every clause earns its place.

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 two-parameter install operation with no output schema, the description covers the required input shape, the common failure cases, and the side effect of reinstalling. Device-selection details are already fully specified in the schema, so nothing necessary for a correct call is missing.

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 100% and the schema already documents both the .app path format and the device-selection rules, so the baseline is 3. The description adds meaning by explaining that .ipa and device builds fail with a confusing error, which sharpens the agent's understanding of the path parameter beyond the schema alone.

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 opens with the specific action 'Install a build' and precisely identifies the target resource as a simulator-built .app bundle. It also clearly separates this from invalid inputs like .ipa and device builds, making the tool's purpose easy to distinguish from sibling tools such as ios_simulator_launch.

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 primary use case is explicit: install a simulator build from a .app bundle. It also gives strong negative guidance by warning that .ipa files and device builds fail. It does not explicitly name an alternative tool for launching or listing apps, but the install operation itself is unambiguous enough that no direct sibling comparison is required.

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