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

Annotations already cover the write nature (readOnlyHint=false) and non-destructiveness (destructiveHint=false). The description adds value by requiring a coordinator role and mandating that creation happen only on explicit user request, which are important behavioral guardrails not present in annotations. It does not over-explain side effects, but for a create operation this is sufficient.

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?

Three sentences with no filler: role, action, scope, sibling routing, and explicit-request guardrail are all front-loaded and actionable. Every sentence earns its place.

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 9-parameter create tool with a 100%-documented input schema and an output schema, the description covers the remaining non-schema essentials: auth requirements, sibling-tool disambiguation, and invocation policy. Nothing critical 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 description coverage is 100%, so the schema already documents all 9 parameters. The description adds useful context that ticketing is optional and that the event is created at the active school, tying to ticket_price_cents/max_capacity and school_slug, but it does not substantially deepen parameter-level 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 ('Creates') and resource ('school event'), and clarifies scope ('at the active school') and optional ticketing. It also names the two sibling tools that handle modifications and registrations, so an agent can distinguish this from update_school_event and register_for_event.

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?

Provides explicit role prerequisites, a WRITE / explicit-user-request condition, and direct routing to sibling tools for change (update_school_event) and registration (register_for_event). This leaves little ambiguity about when to invoke this tool versus alternatives.

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