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

With readOnlyHint=true already declaring the safety profile, the description adds useful scope context: results are limited to sites the developer account can access, and passing site_ids returns more detail per site. It does not mention pagination behavior, but that is covered by the schema.

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?

Two tight sentences with the core purpose front-loaded and no filler. The trailing 'Mindbody: GET /site/sites' is marginally redundant with the resource name but confirms the upstream endpoint.

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 no-required-param, read-only list tool with no output schema and full schema coverage, the description covers scope, the API-key use case, and the two filtering modes. Return shape is left to the reader but is not critical here.

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%, so limit/offset/site_ids are all documented in the schema, including the detail-level difference for site_ids. The description adds no parameter meaning beyond that baseline.

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 (List) and resource (Mindbody sites/businesses) plus the scope of access, and clarifies what a 'site' is via the parenthetical '(businesses)'. An agent can distinguish it from siblings like mindbody_list_locations or mindbody_list_clients.

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?

Offers a concrete use case ('A cheap way to confirm the API key works') and notes the alternate mode for retrieving specific site details. It lacks explicit when-not guidance or named alternatives, but the context for calling it is clear.

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