tool_cursor_position

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly states 'Read-only', indicating no side effects, and specifies that values are in physical pixels, which is critical for coordinate interpretation. This provides meaningful transparency beyond a bare 'returns position' statement.

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 a single, front-loaded sentence that conveys the primary purpose (cursor position and screen size) and a key qualifier (physical pixels), followed by the 'Read-only' trait. There is no wasted prose, and the most important information appears 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?

The tool is simple (no parameters) and an output schema exists (not shown but indicated), so the description need not explain return types. It covers purpose, units, and side-effect nature. Minor details like multi-monitor behavior are not addressed, but for a basic read tool this is adequate. The presence of an output schema reduces the burden further.

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?

The tool has zero parameters, so the baseline is 4 per the rubric. The description adds no parameter semantics (there are none to explain), but it does clarify the output semantics (position and screen size), which is useful context. No gaps exist since there are no parameters to document.

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 returns the current cursor position and screen size in physical pixels, which is a specific purpose distinct from sibling tools like tool_click_at (which manipulates coordinates) or tool_get_window_rect (which returns window bounds). The 'Read-only' phrase further disambiguates it as a query operation.

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 implies usage when an agent needs the cursor position or screen dimensions, but it does not explicitly mention when to choose this tool over alternatives or list exclusions. Since the purpose is self-contained and no alternative is cited, the guidance is implied rather than explicit.

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