Android MCP

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

With only a title annotation and no behavioral annotations (like readOnlyHint, destructiveHint, or rate limits), the description carries full burden but provides minimal behavioral context. It states what the tool does but doesn't disclose whether this is a read/write operation, what happens on failure, if it requires specific permissions, or any side effects. The description doesn't contradict annotations, but adds little beyond the basic action.

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 with zero wasted words. It's appropriately sized for a simple tool and front-loads the core action. Every word earns its place without 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 no annotations, no output schema, and 0% schema coverage, the description is incomplete. It doesn't explain what happens after connection (success/failure states, return values), prerequisites, or error handling. For a device connection tool with potential complexity, this leaves significant gaps for an AI agent.

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 0%, so the description must compensate but adds minimal parameter semantics. It mentions 'by serial number' which clarifies the 'serial' parameter's purpose, but doesn't explain format requirements, where to get the serial number, or validation rules. With 1 parameter and low coverage, this is inadequate compensation.

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 ('Connect to') and target resource ('an ADB device by serial number'), providing specific verb+resource pairing. However, it doesn't differentiate from sibling tools like 'ListDevices' or explain how this differs from other connection-related operations that might exist.

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. It doesn't mention prerequisites (like needing a device to be available), when not to use it (e.g., if already connected), or reference sibling tools like 'ListDevices' that might be needed first. The only implied context is the serial number parameter.

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