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

Beyond the annotations, it discloses two useful facts: the operation costs nothing ('Free') despite sibling credit tools like estimate_cost/buy_credits, and that the underlying set code persists in file names, so naming has no effect on generated assets. The clearing-by-empty-name behavior is also disclosed. It does not address the idempotentHint=false claim (re-naming behaves deterministically in practice), a minor omission rather than a contradiction.

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?

Three short, front-loaded clauses covering the action, an example, the clearing case, a side-effect caveat, and cost — essentially no wasted wording. The parenthetical '(PA-…)' is slightly cryptic but is the only marginally unclear phrase.

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?

A simple two-parameter, non-destructive mutation with annotation coverage and no output schema needs little more than this; cost, reversibility (empty name), and asset-immutability are all stated. Gaps are modest: uniqueness of names, behavior when exceeding the 80-character limit, and the response shape are unaddressed.

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%, so the description must carry meaning, and it does for the critical parameter: 'name' accepts a free-text label, with an example format and the special empty-string semantics that the schema cannot express. 'image_set_id' is left to its uuid format in the schema, with no hint about where to obtain it.

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?

Names a specific verb and resource ('Gives an image set a name') and immediately scopes the effect with an example ('Variant B: warm light') plus the clearing behavior for empty names. No sibling is named explicitly, so differentiation from tools like get_image_set or cancel_image_set is by purpose only rather than by explicit routing.

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?

'for A/B tests' hints at the intended context, and 'an empty name removes it' tells the agent how to undo a naming. However, there is no explicit when-to-use vs. alternative guidance (e.g., use get_image_set first to obtain the id, or use copy_image_to_set instead if a new set is needed).

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