Better Playwright MCP

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

No annotations are provided, so the description carries full burden. It states the tool downloads to a temporary directory and returns a local file path, which is useful behavioral context. However, it lacks details on error handling (e.g., invalid URLs, network failures), file format support, or whether the file persists beyond the session. For a tool with no annotations, this leaves significant gaps in understanding its behavior.

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 extremely concise—a single sentence in Chinese that directly states the tool's purpose and output. It's front-loaded with the core action and has no unnecessary words, making it efficient and easy to parse.

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, no output schema, and a single parameter with full schema coverage, the description is minimal. It covers the basic purpose and output but lacks context on error cases, file management (e.g., cleanup), or integration with sibling tools. For a tool that interacts with external resources and local files, more completeness is needed to guide safe and effective use.

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%, with the parameter 'url' clearly documented in the schema as '图片URL'. The description doesn't add any parameter-specific information beyond what the schema provides, such as URL format requirements or supported protocols. With high schema coverage, the baseline score of 3 is appropriate as the schema handles the parameter documentation adequately.

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 ('下载图片到本地临时目录') and the resource ('图片'), specifying it downloads an image to a local temporary directory. It distinguishes from siblings like 'getScreenshot' or 'captureSnapshot' which capture browser content rather than download external images. However, it doesn't explicitly mention the input parameter 'url' in the description text.

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 'getScreenshot' (which captures browser content) or other file-related tools. It doesn't mention prerequisites, limitations, or typical scenarios for downloading images versus capturing them from the browser.

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