calendar_create_event

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

Annotations already declare the safety profile (readOnly=false, destructive=false, idempotent=true, openWorld=true), so the bar is lower. The description adds genuinely new context: the required 'calendar' permission and that it returns the persisted native ID. It stops short of explaining the approval/_idempotencyKey workflow, but the permission disclosure is real value beyond annotations.

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?

A single front-loaded sentence plus a compact bracketed metadata tag. No wasted words, and the core purpose is stated first.

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 and 100% schema coverage plus annotations covering safety, the description only needs purpose, scope, and permission context, all of which it supplies. The main gap is cross-tool routing guidance, which would round it out.

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 all 9 parameters, including timezone, calendarId, and _idempotencyKey semantics, are already documented in the schema. The description adds no parameter-level detail beyond the schema, so baseline 3 applies.

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 ('Create a single, nonrecurring EventKit event') and scopes it to nonrecurring events, which distinguishes it from a recurring-create or update path. It does not explicitly name siblings like calendar_update_event, but the verb+resource pair is unambiguous.

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?

No explicit when-to-use guidance and no named alternatives. The 'single, nonrecurring' scoping implies the tool cannot be used for recurring events, but the agent gets no routing help vs calendar_update_event, calendar_find_free_slots, or calendar_list_events.

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