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

The annotations establish that this is a non-read-only, open-world, non-idempotent, non-destructive operation. The description adds useful behavioral context beyond that: the 5 MB size limit, supported formats, public URL result, context-cost warning for base64, and the fact that the type is detected from the file itself. It does not disclose whether re-uploading creates duplicates or how uploaded images relate to a project, so it stops short of full transparency.

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 efficient sentences, front-loaded with the primary action and return value. Each sentence adds distinct value: supported formats and size, source preference, and type detection.

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?

The description covers the output URL, format support, size limit, and source choice, which is strong for a tool without an output schema. However, the required project_id is completely undocumented, and the role of file_name is omitted, so an agent must infer how to scope the upload correctly.

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 only 50%, and the description meaningfully clarifies the trade-off between url and base64_data, including that Sendocado downloads from the URL and base64 passes every byte through context. However, it says nothing about the required project_id or the optional file_name, leaving two parameters undocumented in both the schema and description.

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: hosting an image and returning a public URL for use in emails. It also specifies supported formats and the 5 MB limit, which makes the tool's scope immediately clear relative to list_images or delete_image.

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?

It gives clear usage context (for emails) and an explicit preference for url over base64_data because Sendocado downloads the file while base64 passes bytes through context. It does not explain when to choose this tool over sibling image tools such as list_images, but the upload-specific purpose is unambiguous.

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