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

Beyond the annotations (readOnly=false, destructive=false, openWorld=false), the description discloses the asynchronous lifecycle: the link is short-lived, the agent must hand it to the person and wait, poll media_upload_status with the token, and must not publish before status is ready. This is meaningful behavioral context. It stops short of covering auth requirements or failure modes, so a 4 rather than 5.

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?

Purpose and return value are front-loaded, followed by the required workflow, then the alternative and edge case. It is denser and longer than a single-sentence ideal, but every clause carries distinct operational information (wait, poll, do-not-publish, document exception).

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?

With no output schema, the description carries the return burden and does so ('Returns a short-lived link'), and it supplies the full downstream sequence needed to use the result correctly. For a 2-param tool with 100% schema coverage, nothing needed to call it correctly is missing.

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% for both parameters, so the schema already documents note and workspaceId, including the 'leave it out if already decided' guidance. The description adds no parameter-level detail of its own, so the baseline 3 applies.

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 action and artifact ('Ask the person to upload files from their own device. Returns a short-lived link'), and explicitly contrasts itself with media_from_url. An agent can distinguish it from siblings like media_presign or media_complete without opening any schema.

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 an explicit when-to-use condition ('when the file is on their computer or phone') and names the alternative tool with the condition that selects it ('use media_from_url when the file already has a public https address'). It also gives a when-not constraint for the document case (PDF/HWP cannot ride a post).

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