Read image from clipboard

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

readOnlyHint=true already tells the agent this is a safe, non-mutating read, so the description isn't carrying the safety burden. It adds the useful context that the source is typically a screenshot, but says nothing about what happens when the clipboard is empty or non-image, which is the main behavioral risk for a zero-param read.

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 front-loaded sentence that states the action, the resource, and a concrete example with zero filler. Nothing could be trimmed without losing information.

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 output schema and no annotations about return format, the description leaves the agent unaware of how the image is delivered and how failure (no image on clipboard) is signalled. Adequate for a trivial zero-param tool, but the primary edge case an agent will hit is unaddressed.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline of 4 applies. No additional parameter meaning could be added.

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?

States a specific verb (return) and resource (image on the user's clipboard), so the agent knows exactly what the tool fetches. However, it gives no signal distinguishing it from sibling image-capture tools such as device_screenshot or select_region.

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 parenthetical example (a Cmd+Ctrl+Shift+4 screenshot) implies the context where the clipboard holds an image, but there is no explicit when-to-use guidance and no mention of alternatives like device_screenshot for capturing an image directly.

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