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

Annotations already declare non-destructive, idempotent, closed-world mutation, so the safety profile is covered. The description adds one genuinely new trait — 'Free', i.e. no credit cost — but says nothing about whether the original generated title is retained or whether renames propagate to existing publications.

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?

Two sentences, front-loaded with the action and the rationale, with the cost note isolated as a one-word sentence. No filler or restatement of the schema.

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 and all parameters are documented, so return values and inputs need no prose. The only real gap is the missing routing versus edit_creative for a tool set with many overlapping creative-mutation siblings.

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%, with each of the three parameters documented including sourcing hints ('from list_creatives, search_library, get_job or get_upload') and the single-brand omission rule for brandId. The description adds nothing beyond that, 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?

States a specific verb and resource ('Rename a creative in the Library') plus the outcome ('findable by name instead of by its generated title'), so the effect is unambiguous. It does not differentiate from the closest sibling, edit_creative, which an agent could reasonably confuse this with.

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 stated motivation (findability by name vs. generated title) implies when to use it, but there is no explicit when-not or named alternative such as edit_creative or tag_creative. The agent must infer the boundary from sibling names alone.

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