Playwright MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states the action ('Save') but doesn't mention side effects (e.g., file system writes), permissions needed, error conditions, or what happens if the page isn't loaded. For a tool that creates files, this is a significant gap in transparency.

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 front-loads the core purpose without unnecessary words. Every part of the sentence earns its place by specifying what is saved and to what format.

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 annotations and no output schema, the description is incomplete for a tool with 5 parameters that performs file system operations. It lacks behavioral context (e.g., overwrite behavior, error handling) and doesn't explain return values or side effects, which is inadequate for this complexity level.

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 description coverage is 100%, so parameters are fully documented in the schema. The description adds no additional parameter semantics beyond implying PDF generation. Baseline 3 is appropriate since the schema does the heavy lifting, though the description doesn't compensate for any gaps (there are none).

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 ('Save') and resource ('the current page as a PDF file'), making the purpose immediately understandable. It distinguishes from obvious siblings like playwright_screenshot (which captures images) but doesn't explicitly differentiate from other PDF-related tools if they existed.

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 like playwright_screenshot or other file-saving methods. It doesn't mention prerequisites (e.g., needing an active page), exclusions, or comparative contexts with sibling tools.

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