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

With no annotations supplied, the description carries the full burden. It usefully discloses the two-phase upload protocol and that an upload_url is returned, which is behavior the schema does not convey. It says nothing about URL expiration, size limits, permission requirements, or whether an abandoned upload can be resumed or must be cleaned up, leaving significant gaps for a mutation-adjacent tool.

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?

A single front-loaded sentence with zero filler; the protocol step and the handoff to complete_upload are both stated immediately. Nothing is wasted, though the terseness contributes to the gaps scored elsewhere.

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?

It covers the essential call sequence and mentions the key return value (upload_url) despite there being no output schema, which is the most important thing an agent needs. However, four required parameters with low schema coverage and no constraints on file_size or mime_type leave the definition only partially complete for a multi-step upload flow.

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 only 25% — just workspace_id is documented — and the description adds no meaning for filename, mime_type, or file_size. The one behavioral hint it could give (that file_size must match the bytes actually PUT, or which MIME types are accepted) is absent, so it fails to compensate for the coverage 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?

States a specific verb and resource (start a file upload) and explicitly names the follow-up sibling complete_upload, so the agent can place it in the upload flow without inspecting the schema. It does not say what else the response contains besides upload_url, which keeps it short of a 5.

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 clear procedural context: call this first, PUT bytes to the returned upload_url, then call complete_upload. That sequencing is real guidance and routes the agent to the right sibling. There are no exclusions, prerequisites, or notes about when this is inappropriate (e.g., size or MIME limits), so it falls short of a 5.

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