zernio_upload_media_direct

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

The description discloses key behavioral traits: reads from disk, uses multipart/form-data, auto-deletes after 7 days, and max 25MB. However, it does not mention the return value (e.g., a URL or ID for use in messages), which is important for an agent to complete the workflow. Without annotations, this gap reduces 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 concise sentences, each providing essential information: purpose, upload mechanism, and constraints (auto-delete, size limit). No redundant or unnecessary text. Well-structured for quick comprehension.

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 purpose, mechanism, and constraints. Given the simplicity of the tool (2 parameters, no output schema) and no annotations, it is largely complete. However, the absence of return value information (e.g., what to expect after upload) is a minor gap that prevents a perfect score.

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 coverage is 100%, so baseline is 3. The description adds context: 'Reads file from disk' explains filePath usage, 'upload via multipart/form-data' explains the mechanism, and 'auto-detected from extension' explains contentType. This meaningful addition justifies one point above baseline.

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 clearly specifies the tool uploads a local file to Zernio's temporary media storage specifically for use as inbox message attachments. The verb 'upload' and resource 'local file to temporary media storage' are well-defined, and the context of being for inbox attachments distinguishes it from sibling upload tools.

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 description states the tool is for uploading local files for inbox message attachments, providing clear context. While it does not explicitly list when not to use it or mention alternative tools, the specific use case guidance is sufficient for an agent to differentiate from other upload tools.

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