element_screenshot

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

Adding to the annotations (readOnlyHint, destructiveHint, idempotentHint), the description discloses scrolling behavior, format (PNG), and performance profile (cheapest). No contradictions between description and annotations.

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 concise sentences, front-loading key information: purpose, action, and performance. Every word adds value.

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 simple, well-annotated, single-element screenshot tool with no output schema, the description covers all essential aspects: what it does, how it behaves (scroll), and why to use it (cheapest). Complete for agent decision-making.

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% with both parameters described. The description adds no new semantic information beyond the schema; it repeats 'scrolled into view' which is already in the schema. Baseline score of 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 it takes a screenshot of a single element, cropped to that element, and scrolled into view. It explicitly distinguishes from siblings by calling itself the cheapest image, which differentiates it from full-page or screenshot 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 context about when to use this tool by highlighting cost/performance (cheapest) and scope (single element). It implies this is for minimal images, but does not explicitly state when not to use or list alternatives.

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