ariel_upload_image

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

Annotations show this is not read-only and not destructive, and the description clarifies it uploads data and returns a reference rather than directly creating a post. However, it does not mention authentication requirements, upload size limits, or other side effects beyond what the annotations already imply.

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?

One sentence communicates the action, the target system, the return value, and the downstream purpose. Every word is functional and there is no redundancy or filler.

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 three-parameter upload utility with full schema documentation, the description is nearly complete: it states the action and the return value. It falls slightly short by not clarifying how the returned blob reference should be consumed by post-creation tools, but it is still adequate for a helper of this complexity.

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 100%, so the schema already documents all three parameters. The description adds no additional parameter-level meaning beyond calling the input an 'image blob,' which only loosely maps to imageData.

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?

Description uses a specific verb ('Upload') with a clear resource ('an image blob to Bluesky') and states the returned artifact ('a blob reference for use in post creation'). This distinguishes it from sibling tools like ariel_create_post_with_images, which likely upload and attach in one step.

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 'for use in post creation' implies this is a pre-step for posting, but it does not explicitly state when to use this tool versus alternatives like ariel_create_post_with_images. Usage context is implied, not spelled out.

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