Mobile Next MCP Server

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

The annotations already declare readOnlyHint=true, indicating this is a safe read operation. The description adds context by specifying it retrieves the 'current' orientation, implying real-time data, but does not disclose behavioral traits like potential latency, error conditions, or what happens if the device is unavailable. With annotations covering safety, a 3 is appropriate as the description adds some value but not rich behavioral details.

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, clear sentence that front-loads the purpose without unnecessary words. It efficiently communicates the tool's function, making every word count and avoiding redundancy.

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 low complexity (one parameter, read-only operation) and high schema coverage, the description is mostly complete. However, there is no output schema, and the description does not explain return values (e.g., orientation types like portrait or landscape), leaving a minor gap. It compensates well with clear purpose and parameter guidance.

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 the device parameter fully documented in the schema (including a reference to mobile_list_available_devices). The description does not add any parameter semantics beyond what the schema provides, so the baseline score of 3 is applied, as the schema handles the parameter 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 specific action ('Get') and resource ('current screen orientation of the device'), distinguishing it from siblings like mobile_get_screen_size (which returns dimensions) and mobile_set_orientation (which changes orientation). It precisely defines what the tool does without ambiguity.

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 implies usage context (when you need to know the device's orientation), and the input schema's parameter description provides guidance on how to obtain the device identifier via mobile_list_available_devices. However, it does not explicitly state when to use this tool versus alternatives like mobile_get_screen_size or when not to use it (e.g., if you need to change orientation).

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