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

Beyond the annotations (readOnly, non-destructive, closed-world), the description discloses meaningful behavior: previews are approximate because tiles are rescaled from last frames, off-screen workspaces are rendered at the user's window width, and private sites are masked as labelled boxes. These caveats go well past what the structured fields convey.

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 main behavior is front-loaded, but the middle sentences are grammatically broken and run-on ('With width (CSS pixels), a preview of the whole Workspace at that window width instead: ...'), which slows comprehension. Every sentence carries content, but the phrasing could be tightened considerably.

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?

For a two-parameter read-only image tool it covers rendering fidelity and privacy masking well. It still leaves the required workspace identifier undefined and does not indicate how the image is returned (e.g., inline image content), and there is no output schema to fill those gaps.

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 0%, so the description must carry parameter meaning. It handles width well (CSS pixels, effect on output, preview semantics) but says nothing about the required 'workspace' parameter — whether it is an ID, a name, or a handle — leaving the most important input ambiguous.

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 establishes the resource (a Workspace) and the output (a JPEG), and it distinguishes two modes: the current on-screen view versus a full-workspace preview when width is supplied. It does not, however, differentiate this from the sibling 'screenshot' tool, leaving the agent to infer which imaging tool to pick.

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?

It gives explicit conditional guidance for the width parameter ('With width ... a preview of the whole Workspace at that window width instead'), which is genuinely useful. But there is no guidance on when to use this tool versus the sibling screenshot tool, and no prerequisites or exclusions are stated.

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