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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, covering safety. The description adds valuable behavioral context beyond that: it is live from the schedule, has temporal validity (30 minutes after tap, and for the appointment until its day), and returns a waiting state if called before the tap. These details are not derivable from annotations or 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?

The description is three sentences with no fluff. It front-loads the core purpose ('Read the named patient's upcoming appointments...') followed by necessary context about the action_id and the waiting behavior. Every sentence earns its place, and the structure is logical.

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 an output schema present, return values are covered externally. The description covers the tool's purpose, input semantics, temporal constraints, and the waiting state, making it complete for an agent to decide when and how to call it. No critical information appears 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 description coverage is 0%, but the description explains that action_id must come from a booking made in this conversation or from start_xona_appointment_access. It also clarifies the context of the patient tapping the text link. This adds meaning beyond the schema's minimal type/length constraints, although it does not describe the exact format or value pattern beyond its origin.

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 clearly states the action: 'Read the named patient's upcoming appointments at the practice, live from its schedule.' It specifies the resource (appointments), the scope (named patient), and the source (live schedule). It also differentiates from siblings by mentioning the specific trigger condition ('after the patient tapped the text link') and the required action_id types, which are unique to this tool.

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 provides explicit context for when to use the tool: it works with the action_id of a booking made in this conversation (with time constraints) or of start_xona_appointment_access. It also warns that before the tap, the tool reports a waiting state, implying it should not be called prematurely. However, it does not explicitly mention alternative tools or state when not to use this tool, leaving some inference to the agent.

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