Finish a media upload (step 3)

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

Description claims 'Idempotent: re-finalizing the same key returns the existing asset,' which directly contradicts the annotation idempotentHint=false. Per the rubric, any contradiction between description and annotations results in a score of 1.

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 efficient, covering step, precondition, behavior, return value, usage, capability, and safety in a compact format. It is slightly dense but every sentence contributes meaningful guidance; no fluff or redundancy.

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?

Despite lacking an output schema, the description explains the return value (MediaAsset with publicUrl) and its downstream use. It also addresses idempotency, capability (draft), and safety for draft-only tokens, making it highly complete for a multi-step flow with no output schema.

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?

Input schema provides full descriptions for all three parameters (key, contentType, size), achieving 100% coverage. Description adds only reinforcement to use the same values from step 1, but does not add new semantic details beyond the schema, so baseline 3 applies.

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 clearly states the tool's purpose: 'Registers the object as a MediaAsset and returns it' as step 3 of the media upload flow. It distinguishes itself from sibling tools (prepare_media_upload, upload_media) by specifying its position in the sequence and its unique role.

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 call: 'AFTER you have PUT the raw bytes to the presigned uploadUrl from prepare_media_upload.' Also directs the return value usage: 'publicUrl is what you pass to schedule_post mediaUrls.' Provides clear context for the agent to invoke correctly without confusion.

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