execute_script

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

Discloses capabilities: read/modify DOM, trigger events, terminate apps, run Android shell commands. This adds context beyond annotations. However, 'terminate apps' contradicts destructiveHint=false, causing potential confusion.

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?

Four sentences, each earning its place: purpose, usage guideline, browser detail, mobile detail. No fluff, well-structured with key info 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?

Given no output schema, description hints at return values with 'use return'. Could mention error handling or limitations, but sufficient for a general-purpose tool among many siblings.

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?

Adds significant meaning beyond schema: explains browser vs mobile syntax, use of 'return', auto-resolution of string args to elements. Schema coverage is 100%, so baseline is 3, but description elevates to 4.

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 verb 'executes' and resource 'arbitrary JavaScript in browser page context or Appium mobile: commands'. It differentiates from siblings by specifying 'use only when no dedicated tool covers the action', making the purpose distinct.

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 it should be used only as a last resort when no dedicated tool exists. Provides examples for browser and mobile, implicitly excluding standard interactions like click_element, set_value, etc. Lacks explicit 'when not to use' but guidelines are clear.

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