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

Annotations only tell the agent this is a non-destructive, open-world write. The description adds real behavioral detail beyond that: it returns old and new times, it notifies other people (so user confirmation is required each call), confirmation is on by default and can be turned off, and it needs an API key with app access. These are exactly the traits an agent needs before mutating a schedule.

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 key purpose and the confirmation/side-effect warnings are front-loaded and easy to scan. The opening two sentences restate the same move operation (verb+resource, then a longer paraphrase), which is mild redundancy rather than a real cost.

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 non-destructive mutation with a fully documented three-parameter schema and no output schema, the description covers what the agent still needs: return values, side effects on other people, the confirmation default, and the auth requirement. Nothing essential 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%, so the schema already documents appointment_id, start, and provider_id, including that provider_id defaults to unchanged. The description only reinforces that provider is optional and hints where the new start comes from, adding marginal meaning beyond the structured fields.

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?

The description pairs a specific verb (move/reschedule) with a precise resource and scope: one appointment, to a new start time and optionally a new provider. The calendar-drag analogy plus the sibling reference to search_availability makes it clearly distinguishable from vagaro_book_appointment and vagaro_cancel_appointment.

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?

It gives clear context ('Pick the new start from search_availability') and workflow guidance about confirmation. It does not explicitly state when to reschedule rather than cancel-and-rebook, but the routing to the availability sibling covers the main decision an agent faces.

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