observe_device

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

No annotations provided, so description carries full burden. Discloses return formats (PNG, JSON/XML) and performance benefit, but does not mention side effects, permissions, or error conditions. Adequate for a read-only observation tool.

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?

Two sentences plus a bolded important note, all essential. Front-loaded with purpose and deliverables. No wasted words.

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?

Covers purpose, output format, and important usage guidance. Lacks prerequisites (e.g., device connection) and potential limitation details, but sufficient given tool simplicity and no output schema.

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?

Input schema has no parameters, achieving 100% coverage. Baseline of 4 applies as no additional parameter information is needed.

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?

Clearly states it retrieves both screenshot and UI tree, distinguishing from separate calls to screen_capture and dump_ui_tree. Specific verb 'observe' and resource 'device' with explicit deliverables.

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?

Explicitly recommends using this tool instead of separate calls for speed. Includes important post-processing guidance about preferring selector-based interaction over coordinate clicks, but does not explicitly state when not to use the tool.

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