Insert an image

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

No annotations are provided, so the description carries the full burden. It discloses that the edit is direct (not a suggestion) and that certain image formats are unsupported. However, it does not mention auth/account requirements (only present in schema), failure behavior, or reversibility—gaps that could matter for a mutation tool. This is adequate but not rich.

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?

Three sentences, each carrying unique information: purpose + constraints, parameter semantics, and a behavioral caveat. No filler, front-loaded with the core action. Every sentence earns its place.

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 an 8-parameter tool with no output schema and no annotations, the description covers the core purpose, placement, sizing, alignment, and major limitations. It misses explicit handling of the tab parameter (though schema describes it) and does not mention return values or error cases. Still, it is largely complete and far above minimal viability.

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 description explains key parameters beyond the schema: 'at (top/end/or a unique text anchor)', 'width/height (points)', and 'align left/center/right'. It also clarifies the URL must be public. With 75% schema coverage, the description compensates well, though documentId and tab are not described in text (tab is covered in schema).

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 states a specific verb and resource: 'Insert an inline image from a public URL.' It distinguishes from siblings like insert_table (image vs table) and from suggestion tools via 'direct edit, not a tracked suggestion.' It also scopes the operation to inline images and public URLs.

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 phrase 'A direct edit, not a tracked suggestion' tells the agent this tool is not for creating suggestions and differentiates it from suggestion-related siblings. The note that floating/text-wrapped images are unsupported also gives a clear exclusion. However, it does not explicitly name alternative tools such as edit_doc or insert_table for other content types, so it stops short of a 5.

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