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

Annotations already declare readOnlyHint and idempotentHint, and the description reinforces this with 'Read-only, no side effects.' It adds valuable behavioral context beyond annotations: results are scoped to the active school, cancelled tickets are excluded, and the return payload includes ticket status values like paid and checked_in.

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?

Four sentences with no fluff; the key behavioral claim is front-loaded and every sentence adds useful information. The only minor issue is that 'Read-only, no side effects' partly duplicates the annotations, but it is brief and harmless.

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 zero-parameter tool with an output schema and strong annotations, this description is complete: it defines scope, exclusions, returned fields, and links to the two most relevant sibling tools. An agent has everything needed to select and invoke it correctly.

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?

The input schema has zero parameters and schema description coverage is 100%, so the baseline of 4 applies. The description correctly focuses on output and scope rather than parameter syntax, and no parameter-level explanation is needed.

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 ('Returns') and a precise resource: the authenticated user's own event tickets at their active school, including the exact fields returned. It clearly differentiates itself from sibling list tools like list_school_events, list_my_lunch_orders, and list_my_volunteer_signups by scope and resource.

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 names the sibling tool list_school_events for events the user has not registered for, giving a clear when-to-use/when-not-to-use distinction. It also states that the returned ids are required by cancel_my_event_registration, which helps an agent decide to call this tool before attempting a cancellation.

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