focus

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

With no annotations, the description carries the transparency burden. It reveals the key behavioral trait of not entering text and the coordinate-based targeting, but it does not disclose side effects such as whether focus changes are persistent or whether the tool fails on hidden elements. This is adequate but not comprehensive.

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 two sentences with no filler. The first sentence states the core action and constraint; the second provides usage guidance. Every word earns its place.

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?

The tool is a simple coordinate focus command, and the description covers its purpose, a key constraint, and sequencing with related tools. The lack of an output schema is not a major gap here since the expected outcome is clear, though it does not describe response behavior.

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 coverage is 100%, so parameters are already described in the schema. The description adds no extra parameter detail beyond reinforcing that x and y are screen coordinates, which is already in the schema. Baseline 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 action: 'Move input focus to explicit screen coordinates without entering text.' It specifies the resource (screen coordinates) and distinguishes itself from text-entry siblings like type and fill with the explicit 'without entering text' clause.

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 explicit guidance on when to use the tool: prefer semantic interactions when a snapshot ref or selector is available, and use type or fill after focus. This clearly frames the tool's niche relative to alternatives.

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