list_events

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

With no annotations provided, the description carries the burden of disclosing behavior. It mentions ordering ('earliest first') and implies a read operation, but does not explicitly state that it has no side effects, nor does it cover potential limitations like pagination, timezone handling, or behavior on empty ranges. For a simple read tool this is adequate but not rich.

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 exactly two sentences. The first sentence front-loads the core function and ordering; the second adds usage context. There is zero redundancy or fluff, and 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 simple list tool with two optional parameters and an output schema, the description covers purpose, usage, and ordering. The schema handles parameter formats, and the output schema presumably documents return structure. It could benefit from an explicit 'read-only' statement, but that is implied by 'list'. Overall, an agent has enough to call 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 schema provides 100% coverage for both parameters, including format (YYYY-MM-DD) and defaults. The description only refers to 'a date range', adding no new parameter-specific detail. Per the calibration baseline, a score of 3 is appropriate when the schema fully documents parameters.

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 states the specific verb 'List', the resource 'calendar events', and the scope 'in a date range, earliest first.' This clearly differentiates it from siblings like create_event, find_free_slot, and delete_event, which have different purposes. It also explicitly ties to answering calendar questions and pre-scheduling checks.

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 gives clear context: 'Use this to answer questions about what is on the calendar, and before scheduling anything, so you know what is already booked.' It implies read-only usage and when to invoke it, but does not explicitly name alternatives or state when not to use it. Still, the guidance is actionable and sufficient for an agent.

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