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

Annotations already provide readOnlyHint=true, idempotentHint=true, destructiveHint=false, but the description adds meaningful behavioral context beyond that: it dictates a specific error-handling policy (no retry), a fallback action (use File Upload Widget), and a user-interaction constraint (do not ask for public URL). These are not conveyed by annotations, so the description carries its weight here.

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 well-structured, starting with the core purpose and then adding usage/fallback instructions. It is not overly long, but there is slight repetition of 'upload an image/video' and some redundancy in the error list. Still, every sentence adds value and it is front-loaded with what the tool does.

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 single-parameter tool with an output schema, the description fully covers what it does, when to use it, and how to handle failures. It even specifies the response content (endpoint and example request/response) without needing to detail the output schema. The description makes the tool's purpose and fallback behavior clear enough for an agent to act 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 100% — the only parameter, task_type, is fully described in the schema with a clear description and enum. The tool description does not add any extra meaning about the parameter itself. It mentions file types (JPEG, PNG, MP4) but that is about the upload content, not the task_type parameter. Baseline 3 is appropriate because the schema does the heavy lifting.

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 states it 'Returns the upload API endpoint and example request/response for uploading images (JPEG, PNG) or videos (MP4) to YouCam AI.' This is a specific verb and resource, and it distinguishes itself from sibling upload tools by clarifying it is informational, not actually performing the upload. It also contrasts with File-Upload and upload_file tools, making its role unambiguous.

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?

Explicitly says 'Use when the user wants to upload an image/video via the API' and provides a clear fallback: 'If upload cannot be completed for any reason... do not retry. Immediately use the File Upload Widget instead.' It also instructs 'Do not ask the user for a public URL,' which sets boundaries. This is strong when-to-use and when-not-to-use guidance with an explicit alternative.

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