get_screenshot

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

With no annotations, the description takes full responsibility. It discloses the dependency on the screenshot extra and the fallback to install instructions, which is valuable behavioral context. However, it does not mention output format, size limits, or error conditions.

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 concise with three parts: purpose, prerequisite, and parameter details. It could be slightly more streamlined, but it is well-structured and front-loaded with the core action.

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 simple tool (1 required param, no output schema, no nested objects), the description adequately covers purpose, prerequisite, and parameter format. It also hints at the return type (image vs. instructions), but lacks details on supported image formats or performance considerations.

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 only parameter 'url' is described with format guidance ('Full URL including scheme') and an example. Since schema description coverage is 0%, the description fully compensates, adding meaning beyond the schema's basic string type.

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 'Capture a rendered screenshot of a live web page', which is a specific verb-object pair. It distinguishes from sibling tools like get_html or get_active_visitors, as screenshot capture is unique.

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 mentions the prerequisite (Playwright extra) and fallback behavior, but does not explicitly state when to use this tool vs alternatives. No when-not scenarios or sibling comparisons are provided.

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