list_events

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

Annotations already declare readOnly/idempotent/destructive=false, so safety is covered; the description goes beyond them by disclosing that output shape is identical across Microsoft Graph and Google Calendar, and that it returns [] or an error on IMAP-only setups. No rate limits, pagination, or ordering behavior is mentioned, keeping it out of the top band.

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?

Front-loaded with the core verb and range, then progressively adds provider, error, and alternative detail. Every sentence earns its place, though the provider-shape remark is slightly verbose for a list tool.

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?

An output schema exists, so return values need not be re-explained; the description still contributes the provider-agnostic guarantee and the empty/error case. Combined with annotations and a fully documented 2-param schema, an agent has everything needed 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?

Schema coverage is 100%, so the baseline is 3, but the description adds the anchor semantics the schema lacks — both parameters are relative to 'today' and combine into a single closed interval. It does not add format or edge-case guidance (e.g., large values), so it modestly exceeds 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+resource (calendar events) and immediately bounds it with a concrete window formula, [today - days_back, today + days_ahead]. The provider note and the find_free_slots pointer make it clearly distinguishable from sibling list tools.

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?

Explicitly routes the agent: 'To propose meeting times prefer find_free_slots, which already applies working hours and margins' — a named alternative with a selecting condition. It also flags the no-calendar-connected failure case. It stops short of stating when-not to use this tool (e.g., vs. list_accounts for setup discovery), so it is not a full 5.

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