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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds only the sequencing role (pre-resume) and the nature of the returned values; it says nothing about behavior when the upload doesn't exist or is already complete.

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 usage trigger is front-loaded before the return description. Every sentence carries useful 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?

For a one-parameter read tool with full annotations and an output schema, the description covers the essential purpose and timing. The only meaningful omission is any guidance on the uploadId parameter, which is undocumented in both schema and description.

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?

The single required parameter uploadId has 0% schema description coverage, and the description never mentions it, its expected format (pattern, 200-char cap), or where to obtain it. With the schema unable to compensate, the description leaves a real gap.

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 names a specific resource and return content: 'server-confirmed byte offset and length' for an HTTP upload. This distinguishes it from sibling upload tools like dub_create_upload and dub_complete_upload, though it doesn't explicitly contrast with dub_get_project_status.

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?

'Use before resuming an interrupted HTTP upload' gives a clear, conditional trigger that tells the agent exactly when this tool applies. It doesn't name the follow-up tool (e.g., resume/complete) or state what to do if no upload is interrupted, leaving mild inference.

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