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

Adds the auth prerequisite ('needs account token') that annotations do not express, which is genuine behavioral context for a read-only tool. The trailing purchase-policy sentences ('never buy...', 'give me the payment link') are agent conduct rules tangential to a read-only listing tool, so they add length rather than relevant behavior.

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?

The core purpose and use case are front-loaded and efficient, but three sentences restate the same 'ask before buying' rule, which is redundant and pads a description that otherwise needed two sentences.

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?

No output schema exists, and the description compensates by describing the returned shape (URL, status, domains) plus the auth requirement, which is what an agent needs to call and consume this tool. The purchase warnings are extra but harmless to completeness.

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?

Zero parameters, so the baseline is 4; there is nothing for the description to compensate for and it correctly avoids describing nonexistent options.

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 the account's sites') and enumerates the returned fields (live URL, status, pointing domains). It also positions itself against siblings by naming its downstream use ('find a site_id to deploy to or point a name at'), so an agent can distinguish it from deploy_site and point_domain 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?

Explicitly states the context of use: find a site_id for deployment or domain pointing. It gives clear positive guidance but names no exclusions or alternative lookup tools, so it falls short of the 5-level 'when-not/alternatives' bar.

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