list_events

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds value by explicitly stating 'Read-only', defining the return format, and disclosing the error/empty behavior for IMAP-only accounts. This goes beyond the structured metadata and covers auth and edge-case behavior.

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 three sentences, each earning its place: the core behavior, the constraint/error condition, and the alternative routing. It is front-loaded with the essential purpose and keeps the alternative note at the end.

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 output schema exists (covering return fields), the description provides all necessary calling context: the exact date window, the account requirement, the read-only nature, and the recommended alternative. Nothing an agent needs to invoke it correctly 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 coverage is 100% and both parameters are documented, so the baseline is 3. The description adds interpretive meaning by defining the date-range boundaries ('[today - days_back, today + days_ahead]'), which clarifies how the parameters combine beyond their individual descriptions.

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 a specific verb ('list') and resource ('calendar events'), defines the exact date-range scope, and gives example fields. It also distinguishes itself from find_free_slots, making it unambiguous for an agent to select the correct tool.

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?

It explicitly states when to use this tool (for listing events) and when not to (prefer find_free_slots for proposing meeting times), and it mentions the prerequisite (Microsoft Graph calendar) and the fallback behavior for IMAP-only setups. This is clear, actionable guidance.

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