Xcode MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states the action ('Boot') but doesn't explain what happens during booting (e.g., startup time, state changes), whether it requires specific permissions, or what happens on failure. For a tool that likely involves system-level operations, this leaves significant gaps in understanding its behavior and potential side effects.

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, efficient sentence that front-loads the core action ('Boot a specific simulator') without unnecessary words. Every part of the sentence contributes directly to understanding the tool's purpose, making it optimally concise and well-structured.

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 lack of annotations and output schema, the description is incomplete for a tool that likely interacts with system resources. It doesn't cover what the tool returns (e.g., success status, error messages), behavioral nuances like idempotency or side effects, or how it fits into broader workflows with sibling tools. For a boot operation, more context on outcomes and dependencies would be helpful.

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 description mentions 'by device ID', which aligns with the single parameter 'device_id' in the schema. Since schema description coverage is 100% (the parameter is well-documented as 'Simulator device ID or name'), the description adds minimal value beyond what's already in the schema. This meets the baseline score of 3 for high schema coverage.

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 the action ('Boot') and target resource ('a specific simulator by device ID'), making the purpose immediately understandable. It doesn't explicitly differentiate from sibling tools like 'xcode_shutdown_simulator' or 'xcode_launch_app_simulator', but the verb 'boot' is specific enough to imply starting a simulator device rather than other operations.

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 provides no guidance on when to use this tool versus alternatives like 'xcode_list_simulators' (to find device IDs) or 'xcode_shutdown_simulator' (for stopping). It also doesn't mention prerequisites such as having Xcode installed or simulators available, leaving the agent to infer context from sibling tool names alone.

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