Screenshot

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals that the tool 'Returns the image inline, or a file path when the image is large,' which is key behavioral info not in the schema. It does not mention if it modifies state, but screenshots are inherently read-only, so this is acceptable. Missing details like rate limits or auth needs, but these are not critical for a screenshot tool.

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 two sentences, front-loaded with purpose and usage guidance. Every sentence adds value: first defines action and resource, second gives usage context and return behavior. No wasted words.

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 5 parameters, no output schema, and no annotations, the description covers the core purpose, when to use, and return format. It could mention that the tool does not modify the page (though obvious) or clarify the file size threshold for inline vs. file path, but overall it is sufficiently complete for a screenshot tool.

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 coverage is 100%, so the schema already describes all parameters adequately. The description does not add new meaning beyond the schema for parameters, except implying the use of 'current page' (via page_id) or 'specific element' (via eid), which is already clear from schema. Baseline 3 is appropriate.

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 screenshot of the current page or a specific element,' using a specific verb and resource. It distinguishes from sibling tools by advising to 'prefer snapshot or find for reading structure and text,' showing differentiation.

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 explicitly tells when to use the tool ('Use for visual verification or when layout/rendering matters') and when not to ('prefer snapshot or find for reading structure and text'), providing clear context and alternatives.

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