adb_screen_state

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

The description lists the data returned (foreground activity, screen metrics, battery, UI elements) but does not explicitly state that the operation is read-only or non-destructive, nor does it disclose any side effects. With no annotations provided, this transparency is adequate but not thorough.

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 three sentences, front-loaded with the core purpose and listed outputs, followed by value proposition and usage guidance. Every sentence adds meaningful information with no 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?

While the description lists the types of data returned, it lacks details on the overall return format (e.g., is it JSON?); only the UI elements are specified as TSV. Given no output schema, this omission prevents full completeness for a tool combining multiple data types.

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?

Since the input schema already provides 100% coverage for both parameters (clickableOnly and device), the description adds no additional parameter-specific meaning beyond the schema. Baseline score of 3 is appropriate.

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 combined purpose: 'Get a combined screen state snapshot in one call' and lists specific data returned (foreground activity, screen dimensions/density/orientation, battery, TSV of UI elements). It distinguishes from siblings by noting it replaces 3-4 separate tool calls, making its scope unique.

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 explicitly positions the tool as 'Ideal as a first step in any automation workflow,' providing clear context for when to use it. However, it lacks explicit when-not-to-use or exclusion criteria relative to sibling tools.

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