Snapshot

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

Annotations already declare readOnlyHint=true, indicating a safe read operation. The description adds value by clarifying that the tool can optionally capture visual screenshots with or without bounding boxes. No contradictory behavior is mentioned, and additional traits (e.g., performance impact of vision) are not needed.

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 concise sentences with zero filler. Front-loaded with main purpose ('Get the state of the device') followed by optional features. Every sentence adds value.

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?

For a simple two-parameter tool with no output schema, the description covers purpose and parameter semantics. It could briefly note what 'state' includes (e.g., device info, UI layout) but is otherwise complete enough for agent invocation.

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 explain parameter semantics. It does so effectively: use_vision triggers visual screenshots, use_annotation toggles bounding boxes. This provides clear meaning beyond the schema's type/default definitions.

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: 'Get the state of the device.' It specifies optional visual screenshots via use_vision and annotation control via use_annotation. This distinguishes it from sibling tools, which are actions (Click, Type, etc.) rather than state retrieval.

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 explains parameter usage (use_vision, use_annotation) but does not provide explicit guidance on when to use this tool over alternatives or when not to use it. It implies usage for visual context but lacks explicit context differentiation.

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