MCP Appium Server

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

With no annotations provided, the description carries full burden but offers minimal behavioral insight. It states the action ('Set') implying a mutation, but doesn't disclose effects (e.g., whether changes persist, require simulator state, or affect apps), permissions, or error conditions. This leaves significant gaps for a mutation tool with zero annotation coverage.

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, direct sentence with zero wasted words, front-loading the core action. It efficiently communicates the tool's purpose without redundancy or unnecessary elaboration, making it easy to parse quickly.

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 mutation tool with no annotations and no output schema, the description is insufficiently complete. It lacks details on behavioral traits (e.g., side effects, prerequisites), usage context, or return values, leaving the agent with minimal guidance beyond the basic action and parameters.

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 100%, with clear parameter descriptions in the schema (e.g., 'UDID of the simulator', 'Latitude coordinate'). The description adds no additional parameter semantics beyond implying coordinates are involved, so it meets the baseline of 3 where the schema handles documentation adequately.

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 ('Set') and target ('location of a simulator'), making the purpose immediately understandable. It distinguishes from siblings like 'xcode_clear_simulator_location' by specifying setting rather than clearing. However, it doesn't specify what type of location (e.g., GPS coordinates) beyond what the parameters imply, keeping it from a perfect score.

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?

No explicit guidance on when to use this tool versus alternatives is provided. The description doesn't mention prerequisites (e.g., simulator must be booted), exclusions, or compare with related tools like 'xcode_clear_simulator_location' or general location-setting methods. Usage is implied through the action but lacks contextual direction.

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