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

With no annotations provided, the description carries the full behavioral burden and does so strongly. It discloses conditional side effects (becomes ready vs. discarded), a hard safety boundary ('never deletes a verified ready creative'), and explicit non-returned values such as hash, storage key, provider URL, and tenant identifier.

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?

Four dense sentences with no filler. The purpose is front-loaded, the parameter requirement comes second, the conditional behavior third, and the safety exclusions last. Every sentence contributes distinct 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 mutating cleanup tool with no annotations and no output schema, this description covers purpose, parameter provenance, conditional outcomes, and negative guarantees. It is slightly incomplete in that it never states the success/error return shape and does not explicitly compare itself to sibling tools like creatives_confirm_upload, but these are minor gaps against an otherwise thorough definition.

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 coverage is 0%, so the description must compensate, and it does: it names all four parameters and adds meaning by specifying file_hash is SHA-256, idempotency_key must be stable, and all values should match those from creatives_request_upload_v2. It does not expand on folder_id nullability or upload_attempt default, but the schema already provides those details.

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 specifies a concrete action — 'Reconcile or discard one exact tenant-owned pending/error upload' — attached to a clear motivation: a failed browser upload should not remain as a permanent library placeholder. It also distinguishes itself by explicitly stating that it never deletes a verified ready creative and references the upstream creatives_request_upload_v2 workflow.

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?

The description gives firm when-to-use context by explaining the conditional outcome: if bytes reached storage and verify, the creative becomes ready; otherwise the placeholder is discarded. It also instructs the caller to pass the same parameters used for creatives_request_upload_v2. However, it does not explicitly route the agent away from sibling tools like creatives_confirm_upload or creatives_reconcile.

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