Create a calendar event

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

Beyond annotations (readOnlyHint=false, idempotentHint=true, etc.), the description adds key behavioral traits: time zone handling (local wall-clock, never UTC), idempotency via transactionId, and system-side default time zone. No contradiction with 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?

The description is concise, front-loaded with purpose, and contains only essential information. Every sentence adds value, and important notes are flagged with 'IMPORTANT'.

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?

Given the complexity (8 params, nested objects, no output schema), the description covers idempotency, time zone details, confirmation step, and return behavior indirectly (echo back the created event). It is complete enough for correct invocation, though explicit return structure would push it to 5.

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 100%, so baseline is 3. The description adds value by highlighting the time zone nuance (local wall-clock, never UTC Z) and idempotency key, which go beyond the schema descriptions. This justifies a 4.

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 uses a specific verb and resource ('Create a calendar event') and includes an example ('e.g. a booking, plus separate travel-time blocks'), clearly distinguishing it from siblings like list_events and update_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?

The description advises confirming details with the user before calling and echoing back the created event, providing clear usage context. It does not explicitly mention when not to use or list alternatives, but the guidance is sufficient.

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