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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The only added context is "bounded upload metadata," which is vague and unexplained, and the description says nothing about idempotency behavior, retry semantics, or metadata expiry despite idempotency_key and upload_attempt parameters being present.

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 short sentence, front-loaded with the action, with no filler. It is efficient, though the brevity edges into under-specification rather than tightness.

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?

An output schema exists, so return values need not be described, but with 8 undocumented parameters, a mutation-style operation, and a clear sibling flow, the description leaves too much for the agent to infer. It is not adequate for a tool of this complexity.

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 0% across 8 parameters, so the description carries the full burden — and it adds nothing. It never explains filename, file_hash, file_size, content_type, folder_name, upload_attempt, idempotency_key, or the connection_context pattern.

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 gives a verb+resource ("Prepare a creative upload") but "prepare" is ambiguous and it never distinguishes itself from close siblings like creatives_confirm_upload or creatives_abandon_upload, which clearly belong to the same flow. An agent can guess it starts an upload, but cannot tell from this text where it sits in the sequence.

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?

There is no when-to-use guidance, no mention that this is the first step of a request/confirm/abandon sequence, and no prerequisites. The sibling set strongly implies a multi-step upload flow, yet the description offers no routing help.

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