media.upload

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It clearly states the tool performs an external upload and returns URL and dimensions. However, it omits authentication needs, file format/size constraints, and behavior around overwriting or duplicate uploads.

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?

The description is a single sentence with no filler. It front-loads the action and economically communicates the target and the return value.

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 tool is simple and has an output schema, so return values need not be re-explained. However, the singular required parameter is undocumented and there is no guidance on prerequisites or constraints, leaving a significant gap for reliable invocation.

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 schema has one required parameter, 'path', with 0% description coverage, and the tool description never explains what 'path' means. An agent cannot tell whether it is a local file path, remote URL, CDN key, or some other identifier.

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 ('upload'), an explicit resource ('image to Xianyu CDN'), and the return value (URL + dimensions). It is clearly distinguishable from all sibling tools, none of which are media upload operations.

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?

Usage is implied: an agent would understand the tool is for uploading an image to the CDN. However, there is no explicit when-to-use or when-not-to-use guidance, nor any mention of alternative tools.

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