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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuine behavior beyond them: a two-phase commit ('until this succeeds the file is not added') and the retry semantics ('registering again after success returns the same result'). It omits one behavioral detail an agent may need — how the destination (Illustrations vs. vault folder) is chosen, since no destination parameter exists.

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 sentences, front-loaded with the precondition and destination before the retry notes; nothing is padded. The closing pair of sentences about re-registering is slightly redundant with the idempotent annotation and could be tightened into one clause.

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?

A confirmed-write tool with an output schema, so return values need not be explained, and the description covers the workflow, the failure/retry path, and the post-success no-op. The remaining gap is the destination-selection mechanism, which matters for a tool that can write to two quite different places.

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 100% and both parameters are documented there, including the 'Illustrations only' scoping of description, so the baseline is 3. The description's only parameter-adjacent content ('the same upload', 'what the drawing shows') restates the schema rather than adding format, constraints, or defaults.

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 uses a precise verb and resource ('Finishes an upload') and anchors it to the exact upstream step, the PUT to the URL from request_upload_url. It also names the two possible destinations (Illustrations section of an innovation vs. vault folder), which lets an agent separate this from request_upload_url and create_asset 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?

It states the precondition for calling (file must have been PUT to the URL from request_upload_url) and handles the retry case explicitly: if the file has not arrived or Lightbringer asks to try again, the same upload can be re-registered. It does not explicitly say what not to use it for or name a competing tool, which keeps it just below a 5.

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