clipboard_copy_image

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

Annotations (destructiveHint=true, idempotentHint=true, readOnlyHint=false) are consistent with the description, which adds genuinely new behavioral context: the clipboard is overwritten, MIME headers are verified against the declared type, no re-encoding occurs, and a byte-size ceiling keyed to MCP_CLIPBOARD_MAX_IMAGE_BYTES applies. This is well beyond annotation coverage.

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?

Front-loaded with the core action, then cleanly sectioned into WHEN/Args/Returns/Limits, and the Args details are load-bearing given the empty schema. The Returns block is mildly redundant since an output schema exists, keeping it just short of a 5.

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 2-param destructive write with an output schema, the description supplies everything material: trigger conditions, encoding contract, MIME restrictions, size limit and how to raise it. Nothing an agent needs to call it correctly is missing.

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 description coverage is 0%, so the description carries the full burden and does: `image_data` is base64 bytes interoperable with `clipboard_paste`, and `mime_type` accepts only image/png or image/jpeg with header verification. Both parameters are disambiguated with syntax and constraints the schema lacks.

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?

Opens with a specific verb+resource: 'Write an image to the user's system clipboard.' It immediately scopes the tool to images and explicitly routes text content to `clipboard_copy`, so the agent can distinguish it from the sibling text tools without reading any schema.

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?

A dedicated WHEN TO CALL section gives trigger phrases ('copy this image', 'put this on my clipboard') plus a second scenario (produced/fetched images to paste elsewhere), and names the alternative `clipboard_copy` for text. Explicit when and when-not coverage.

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