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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds real context: semantic search only exists in some workspaces, results mirror list_creatives' fields, and output is truncated when matches exceed limit. The one gap is that truncation is disclosed without saying how to retrieve the remainder beyond raising limit.

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 sentences, no filler: capability first, then the positive use case, then the exclusion and its alternative. Each sentence changes agent behavior, and the routing-critical constraint is stated plainly rather than buried.

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?

With an output schema present, return values needn't be detailed, and annotations cover safety; the description fills the remaining needs (capability variance, truncation, sibling routing). Only the undescribed assetTypes filter leaves a small hole for a four-parameter tool.

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 75%, so the schema already documents limit, query, and brandId. The description still adds meaning the schema lacks: that query matches both name/title and visual content, the latter only where semantic search is enabled — a distinction that changes how an agent should phrase queries. assetTypes remains undescribed in both places.

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 (find creatives in the brand's library) and names both search modes: filename/title matching and, conditionally, semantic visual matching. It also distinguishes itself from list_creatives (same return shape) and request_image_upload, so an agent can route correctly without opening a schema.

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?

Gives an explicit when-to-use (locate an existing creative before generating a new one, when the user asks for something they already own) and an explicit when-not (an image pasted/attached in chat is not in the library — call request_image_upload instead). This is the strongest possible routing guidance.

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