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

Annotations already declare readOnly/idempotent/non-destructive, so the description isn't burdened with safety. It adds real value beyond that: times are rendered on the business clock and the visitor's clock when they differ, `needs_time` results come back under a `requests` key, and registration/enrolment rows carry claim_id, status, places and payment. A brief privacy constraint is also included.

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 in the first clause, then the enum detail follows. The text is dense with parentheticals and long sentences, but nearly every clause carries information an agent needs (enum semantics, response key naming, timezone behavior). Minor trimming would help readability.

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?

With no output schema, the description carries return-shape information (requests key, claim_id/status/places/payment) and timezone semantics, which is exactly the gap it needs to fill for a read-only list tool. Remaining unknowns like `limit` behavior are minor against a well-covered view/week_of surface.

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 67%, and the description substantially compensates: it defines all seven `view` enum meanings (the schema only lists them) and clarifies that `week_of` returns a Monday–Sunday calendar with per-day open hours, time off and appointments. It is silent on `limit`, `contact_id` and `user_goal`, which are left to the schema.

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 ('A site's appointments') plus scope details (timezone rendering, view modes) that let an agent tell it apart from mutation siblings like update_appointment or manage_appointments. It never explicitly contrasts with nearby read siblings such as get_appointments_status, get_calendar or list_events, so it stops short of full differentiation.

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?

The description enumerates every `view` value and explains the `week_of` alternative mode, which implicitly guides selection between output modes. However, it gives no guidance on when to call this versus get_appointments_status, get_calendar, or list_events — the sibling choice is left to inference.

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