screenshot

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

No annotations are provided, so the description carries the full disclosure burden. 'Visible part' usefully signals that off-screen content is excluded, but nothing is said about the return format (image data vs. path), permissions, or side effects.

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?

A single short sentence with no waste and the key scoping qualifier ('visible part') front-loaded. Its brevity, however, tips into under-specification rather than disciplined conciseness.

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?

With no annotations, no output schema, and an undocumented parameter, the description is too thin for an agent to call this confidently—especially since the return format of a screenshot tool is a critical unknown.

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?

One parameter (tab_id) with 0% schema description coverage and a null default. The description never mentions tab_id or explains what happens when it is omitted (e.g., capturing the active tab), so it does not compensate for the schema gap.

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 phrase 'Screenshot of the visible part of a tab' identifies the resource (a screenshot) and the scope (visible viewport of a tab), which distinguishes it from read_page/get_text. However, it's a noun phrase with no verb and no explicit statement of what the tool does (capture/return an image), leaving the action implied rather than stated.

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?

There is no guidance on when to use this tool versus siblings like read_page, get_text, or scroll. The word 'visible' hints at a viewport-only scope but never says to scroll first or when a screenshot beats text extraction.

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