render-screenshot

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

With no annotations, the description carries the full burden of behavioral disclosure. It mentions the return format and lists supported features (device emulation, dark mode, ad/cookie/tracker blocking, geo-targeting, full-page), which is helpful. However, it does not disclose any potential failures, auth requirements, rate limits, or the nature of the returned URL (e.g., temporary vs. permanent), leaving gaps in behavioral context. It is adequate but not thorough.

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 two sentences that front-load the primary action and return info. It avoids redundancy and is easy to scan. It could be slightly more structured (e.g., separating features), but it is efficient and clear.

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 tool has 15 parameters and no output schema, the description provides only a high-level overview. It fails to mention how it differs from the sibling 'get-screenshot', which is critical for tool selection. It also does not mention any constraints (e.g., URL accessibility, authentication) or elaborate on the returned image URL's properties. This incompleteness leaves an agent uncertain about when and how to use it correctly.

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 baseline is 3. The description references many features that map to parameters (e.g., dark_mode, block_ads, country, full_page), but these are already well-described in the schema. The description adds little semantic value beyond grouping these features together; it does not clarify any parameter's deeper behavior or edge cases.

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 verb 'Capture' and the resource 'screenshot of any website URL', and also mentions the return values (image URL, dimensions, file size). However, it does not differentiate from the sibling tool 'get-screenshot', which likely performs a similar function, so it loses a point for not distinguishing between similar tools.

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 'get-screenshot' or 'capture-element'. It simply states what it does without any context on selection criteria, prerequisites, or exclusions. An agent would have no basis to choose this over its siblings.

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