Playwright MCP Server

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 mentions the action but fails to describe key traits like file storage behavior (e.g., where screenshots are saved), default formats, or potential side effects (e.g., if it modifies page state). This leaves significant gaps for a tool with 8 parameters and mutation implications.

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, clear sentence that directly states the tool's purpose without unnecessary words. It is front-loaded and efficient, making it easy to understand at a glance, which is ideal for conciseness.

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 the complexity of 8 parameters, no annotations, and no output schema, the description is inadequate. It lacks details on behavioral aspects (e.g., file handling, defaults), usage context, and output format, leaving the agent with insufficient information to use the tool effectively beyond basic intent.

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 input schema has 100% description coverage, providing detailed documentation for all 8 parameters. The description adds minimal value beyond the schema, only implying the 'selector' parameter for element-specific screenshots. This meets the baseline of 3 since the schema handles most of the parameter semantics effectively.

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 ('Take a screenshot') and the target ('current page or a specific element'), which is specific and actionable. However, it doesn't distinguish this tool from potential screenshot alternatives among siblings (like playwright_save_as_pdf), though no direct screenshot sibling exists in the provided list.

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 no guidance on when to use this tool versus alternatives, such as playwright_save_as_pdf for PDFs or other screenshot methods. It lacks context about prerequisites (e.g., needing an active page) or exclusions, offering only a basic statement of functionality.

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