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

Beyond the annotations, the description discloses billable AI usage, synchronous execution, partial failure behavior, idempotency retry semantics, and the requirement to use assistantSummary rather than raw JSON. No contradiction with annotations is present; the idempotentHint aligns with the deterministic retry key statement.

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 core purpose is front-loaded in the first sentence, but the description is a long block of operational policies. It is somewhat repetitive, mentioning 'deprecated alias' in both the title and text, and the dense packing of rules reduces readability. Most sentences add value, but the structure could be improved.

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?

The description covers mutation behavior, idempotency, seat requirements, and output presentation, which is useful for a complex 27-parameter tool. However, it does not address many optional params or their interactions, leaving gaps for callers needing to use force, template, instructions, or requestedFormats. Since an output schema exists, return-value details are reasonably delegated to that 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?

With 27 parameters and 0% schema description coverage, the description must carry most parameter semantics. It explains creativeIds/persistence, idempotencyKey, and seatId/seatName, and provides high-level concepts like campaign context and brand rules, but leaves many parameters (force, input, assets, template, objective, instructions, etc.) unexplained. Some referenced modes, such as validate_only and saveToStudio, do not exactly match the schema's persistence enum.

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 opens with a precise verb and resource: 'Generate Studio-ready design briefs for one or more creatives,' listing the key inputs used. It further distinguishes itself by explicitly stating it is a deprecated alias for create_creative_brief, which differentiates it from the canonical sibling tool.

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 provides explicit conditional guidance: saves only when creative IDs and saveToStudio are supplied and the caller has Studio write permission, otherwise returns a non-destructive proposal. It also states execution mode, task support being forbidden, mutation modes, partial-failure policy, and the seat requirement for multi-seat writes.

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