upload_asset_begin

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

Even with no annotations, the description discloses key behavioral traits: it initiates a chunked upload, returns an uploadId, and that ID expires after 10 minutes of inactivity. It also explains the underlying reason (LLM→tool_call boundary truncation). It doesn't cover permission requirements or side effects, but the session semantics are well conveyed.

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 dense but perfectly scoped: three sentences covering purpose, when-to-use, the full flow, the return value, and the expiry. Every sentence adds unique value, front-loaded with the most critical information, and avoids fluff.

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 multi-step operation with several sibling tools, the description is remarkably complete. It names the sibling steps, explains the advantage over upload_asset, notes the return value (uploadId) and its lifecycle, and sets expectations for the flow. No output schema exists, so the description's note about returning uploadId fills that gap.

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 high (88%), so the schema already documents most parameters (fileName, sha256, fileSize, etc.). The description adds no additional parameter-level detail beyond naming fileName implicitly and implying the upload flow. It meets the baseline for high schema coverage but doesn't elevate it.

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?

Description opens with a specific verb+resource ('Start a chunked asset upload') and immediately distinguishes from siblings: 'Use this instead of upload_asset's fileBase64 param for large files'. It clearly positions this as the first step in the chunked upload flow, differentiating from upload_asset_chunk and upload_asset_finish.

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 states when to use this tool instead of upload_asset (large files over remote/HTTP transport where base64 might truncate), and provides the exact sequence: upload_asset_begin → upload_asset_chunk → upload_asset_finish. This gives the agent clear decision criteria and workflow context.

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