double_click

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

With no annotations, description covers key behaviors: word selection, allowlist requirement. Does not detail error behavior or multi-display handling, but sufficient for a simple click action.

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, no extraneous words. Action, effect, and constraint are front-loaded.

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?

Simple tool with no output schema; description covers purpose, effect, and usage prerequisite completely.

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 describes both parameters fully (coordinate as array, text as modifier keys). Description adds no extra detail beyond referencing key tool syntax, providing no new semantic value.

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?

Description clearly states action ('Double-click at given coordinates') and effect ('Selects a word in most text editors'), distinguishing it from sibling click tools like left_click and right_click.

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 states prerequisite: frontmost application must be in session allowlist, and behavior if not. Lacks explicit comparison to alternatives but provides actionable context.

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