Playwright MCP Server

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

No annotations are provided, so the description carries full burden for behavioral disclosure. 'Navigate to a URL' implies a browser navigation action but doesn't disclose critical traits: whether it launches a new browser instance, manages browser lifecycle, requires prior setup, handles errors, or what happens on timeout. For a 7-parameter tool with no annotation coverage, 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, efficient sentence with zero waste. It's appropriately sized for a simple verb-noun phrase and front-loads the core action. Every word earns its place, making it easy to parse quickly.

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 (7 parameters, no annotations, no output schema), the description is incomplete. It doesn't explain the tool's role in the Playwright ecosystem, how it integrates with sibling tools, what it returns (e.g., page object, success status), or behavioral nuances. For a navigation tool with rich parameters but minimal description, this leaves significant gaps for an AI agent.

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 the schema fully documents all 7 parameters (e.g., browserType, headless, timeout). The description adds no parameter-specific information beyond what's in the schema, such as explaining interactions between parameters or typical use cases. With high schema coverage, the baseline is 3, and the description doesn't compensate with additional semantics.

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 'Navigate to a URL' states the basic action (navigate) and target (URL), but is vague about scope and differentiation. It doesn't specify this is for browser automation using Playwright or how it differs from sibling tools like playwright_get (which likely serves a similar navigation purpose). The purpose is understandable but lacks specificity and sibling distinction.

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. With sibling tools like playwright_get (which might also navigate) and playwright_click/playwright_fill (for post-navigation actions), there's no indication of context, prerequisites, or exclusions. Usage is implied only by the tool name, not described.

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