take_screenshot

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

Discloses where screenshots are saved (MCP_SCREENSHOT_DIR env var, default system temp). No annotations provided, so description adequately covers behavioral aspects.

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?

Well-structured with Purpose, Parameters, Returns sections. Informative without verbosity, though could be slightly more concise.

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 one parameter and no output schema, description covers purpose, usage, parameter meaning, and return structure. Complete for the tool's simplicity.

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?

Only parameter session_id is described as 'Active browser session identifier.' Schema has 0% coverage, so description adds crucial meaning beyond type and title.

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?

Explicitly states 'Capture a screenshot of the current browser window.' Clearly distinguishes from sibling tools like click_element or open_browser.

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?

States 'Useful for debugging, failure reporting, or visual analysis.' Provides clear context for when to use, though no explicit exclusions or alternatives among siblings.

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