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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered structurally. The description adds nothing beyond the schema's own date-range constraints — no mention of pagination, result caps, ordering, or what happens when a connection is disconnected or lacks calendar scope.

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 with no filler. It is efficient, though its brevity is partly under-specification rather than disciplined compression.

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 read-only list tool with good annotation coverage, the minimum needed to call it is present. But with 5 parameters, a required connectionId, and several near-duplicate calendar-listing siblings, the description should resolve which calendar surface it targets and how results are bounded.

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 80% and the schema documents connectionId provenance, from/to ISO 8601 semantics, and calendarId defaulting to primary. The description only restates the date-range framing and adds no syntax or edge-case detail, so the 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 ('List events from a connected calendar') scoped by a date range, which is clear on its own. However, it never distinguishes itself from the very similarly named sibling list_calendar_events, nor from get_connection_event, so an agent cannot tell from the text which of these is the right entry point.

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?

There is no explicit guidance on when to use this versus list_calendar_events, get_connection_freebusy, or list_calendar_connections. The only implied signal is that a connectionId is required and can be obtained from list_calendar_connections, but that comes from the schema, not the description.

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