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

Annotations only declare the safety profile (readOnly=false, destructive=false). The description adds the essential workflow context they lack: a two-step process, that bytes must be PUT with a matching Content-Type, and that the returned key can serve as an r2Key. This is real behavioral disclosure beyond structured fields.

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?

Two dense sentences with zero waste, front-loading what the tool returns before the mechanics and the alternative. Every clause carries actionable information.

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 takes on return-value disclosure and does it well (uploadUrl, publicUrl, returned key), and it closes the loop on where the result goes. Nothing an agent needs to invoke 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 coverage is 50%: contentType is documented and filename is not. The description reinforces the Content-Type matching requirement but adds nothing about filename beyond the schema's length constraints, so the baseline 3 for schema-carried semantics is appropriate.

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?

States a specific action (get a presigned PUT URL) and resource (upload target for image/video/audio), plus what is returned (uploadUrl and publicUrl). It is clearly distinguishable from the closest sibling, import_asset_from_url, which is explicitly named.

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?

Explicit when-to-use and when-not-to-use: 'Prefer import_asset_from_url when you already have a URL.' It also routes the output to named downstream consumers (transcribe_media, create_voice_clone samples, voice_enhance), giving the agent the full context for choosing this tool.

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