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

No annotations are supplied, so the description must carry the behavioral burden, and it does: it discloses the 10-minute validity window, the exact upload protocol (PUT with upload_headers, Content-Length, no Authorization header, curl example), and the required next call. These are non-obvious operational constraints that prevent failures.

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 dense sentences, front-loaded with what the tool does and what it returns, followed by the required upload procedure. The curl example earns its place by making the exact headers and no-Authorization rule concrete.

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 two-parameter tool with no annotations and no output schema, it covers the creation and upload lifecycle thoroughly, including the mandatory follow-up call. Minor gaps: it doesn't say how to recover if the 10-minute PUT window lapses (new upload vs. reuse id), and it doesn't tie bytes to Content-Length.

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 0%, so the description needs to compensate. It explains filename semantics (only the extension is used) and implies bytes is the file size subject to the 2 GB limit, but never explicitly states that bytes must equal the file's byte length or that it matches the Content-Length: N in the upload request.

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 ('Start an upload') and resource ('local .edf, .bdf or .npy file'), plus the size cap and returned values (id, presigned upload_url). It also names start_embedding_job as the follow-up, so an agent can distinguish it from 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 explicit constraints and sequencing: allowed extensions, at most 2 GB, PUT within 10 minutes with exactly upload_headers, then call start_embedding_job with the id. The 'Only the extension of filename is used' note precludes the misconception that the path matters.

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