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

Adds substantial behavior beyond the annotations: imports may overwrite existing directory fields, consume provider credits, and draw on a limited daily discovery budget, plus an async 'pending' status that returns retry_after_seconds. These cost, mutation, and async semantics are exactly the context annotations can't convey, and they are consistent with destructiveHint=true and openWorldHint=true.

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?

Purpose is front-loaded and the three substantive sentences each carry distinct information (import trigger, cost/mutation warning, async status, plan prerequisite). Slightly weakened by the retry_after_seconds detail, which overlaps the output schema, and a boilerplate docs link.

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?

For a single-parameter tool with an output schema and full annotations, the description covers mutation risk, credit/budget cost, async behavior, and auth prerequisites. Nothing needed to call it safely and correctly is missing.

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?

Only one parameter and schema coverage is 100%, so the schema already documents the 'Brand website URL or domain' field. The description restates 'by website URL' without adding format, normalization, or parsing detail, so it meets the baseline without adding value.

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 (find/look up), a concrete resource (a brand and its creator-collaboration contacts), and the exact key used (website URL), plus the fallback import behavior. The URL-keyed mechanism implicitly and clearly separates it from sponsor_search_brands (query-based) and sponsor_get_brand (ID-based) without opening either 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 clear context for using it (you have a website URL) and explains the auto-import when the directory lacks the brand, plus eligibility constraints (Creator Max or agency Pro/Scale/Enterprise). It does not explicitly name the alternative to pick when you only have a brand name, so it stops short of full when/when-not routing.

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