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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false; the description reinforces this by promising a name already in the folder 'is refused, never written over,' which tells the agent collisions fail rather than overwrite. It also discloses the /attachments bypass. It does not say what a successful call returns, which is the main remaining behavioral gap.

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 sentences, no filler, and the sequencing and conflict behavior are front-loaded before the exclusion clause. Every clause carries information an agent would otherwise have to guess.

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 one-required-parameter finalization step with no output schema, the description covers the prerequisite, the exclusion, and the conflict policy. The only omission is what a successful call yields (e.g., the filed path or file id) that an agent might need to chain further calls.

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 upload_id, context, and llm_model are already documented, and the description adds only the provenance hint that upload_id comes from upload_link. That is a marginal gain over the schema, so the baseline 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?

States a specific verb and resource ('files it in that drive') and situates it in the two-step upload flow that begins with upload_link. An agent can tell it apart from upload_link, add_attachment, and other siblings without opening a 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?

Gives the precondition (the file was already PUT to an upload_link for that drive path) and an explicit exclusion ('Not needed for /attachments'), which is exactly the when-not guidance an agent needs. It stops short of saying what to do if the file should replace an existing one, but the conflict rule below covers the outcome.

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