agent-droid-bridge

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

With no annotations provided, the description carries full burden and does well by explaining key behavioral aspects: it returns XML format, should be used sparingly for performance reasons, and has a specific use case pattern with sibling tools. It doesn't mention error handling or performance characteristics beyond usage frequency.

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?

Perfectly structured with three focused sentences: purpose statement, usage guidance, and alternative approach. Every sentence adds value with zero redundancy or fluff. The most important information (what it returns) comes first.

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?

Complete for a read-only tool with good annotations (though none provided) and output schema. The description covers purpose, usage patterns, performance considerations, and relationships with sibling tools. With output schema handling return values, no additional information is needed.

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%, so the schema already fully documents the single parameter. The description adds no parameter-specific information beyond what's in the schema, meeting the baseline expectation 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 tool's purpose with specific verb ('Returns') and resource ('current Android screen as an XML UI hierarchy'). It distinguishes from siblings by focusing on XML hierarchy extraction rather than screenshots, change detection, or direct interaction.

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?

Explicit guidance is provided: 'Use this when you need to locate element coordinates, read text, or find resource IDs to interact with.' It also specifies when NOT to use it ('Do not call this after every action') and names an alternative approach ('use snapshot_ui before the action and detect_ui_change after').

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