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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds useful context beyond annotations by explaining the data-scope effect of omitting `place_slug` and by listing the returned fields such as billing cycle and checkout URL.

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 tightly structured sentences: purpose first, then parameter guidance, then return contents. There is no filler, and the most important usage constraint is front-loaded.

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 optional-parameter, read-only list tool, the description covers purpose, usage condition, omission behavior, and return fields. With annotations handling safety and no output schema needed, nothing material 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?

Schema coverage is 100%, and the schema already calls `place_slug` strongly recommended. The description adds meaning by tying it to `search_places`, giving venue examples, and emphasizing that omitting it returns the directory's own plans rather than a venue's.

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 ('List membership or subscription plans') and clarifies the Wix Pricing Plans context. It also distinguishes the two possible scopes — venue plans vs. directory-site plans — so an agent can tell exactly what this tool returns.

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?

Explicitly says to pass `place_slug` from `search_places` and that this is 'what you want in almost every case.' It also names the fallback behavior when the parameter is omitted, giving clear when-to-use and when-not-to-use guidance.

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