google_calendar_list_calendarsRetrieve calendars accessible to a Google account, including pagination support, so AI agents can identify available calendars before scheduling or managing events.
List calendars the account can access.
| Name | Required | Description | Default |
|---|---|---|---|
| account | No | Account nickname to use. | |
| pageToken | No | Page token from a previous result's nextPageToken. |
Changes observed during successful MCP inspections.
v0.1.95Input schema / properties / pageTokenAdded value: +{
+ "description": "Page token from a previous result's nextPageToken.",
+ "type": "string"
+}v0.1.30Input schema / additionalPropertiesRemoved value: -falsev0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden but only discloses access scoping ('the account can access'). It omits pagination behavior despite a pageToken parameter, whether the primary calendar is included, ordering, and any read-only/safety context. This is thin for an unannotated tool.
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 zero wasted words. It states purpose and scope immediately.
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 two-parameter read tool with full schema coverage, the description covers the core action. However, it lacks pagination guidance and any behavioral context that would be needed in the absence of annotations, leaving it minimally adequate.
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 100%, so both parameters (account, pageToken) are already documented in the schema. The description adds no parameter-level meaning beyond what structured data provides, which is the baseline for full coverage.
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 (List) and resource (calendars) with the scope 'the account can access,' which inherently distinguishes it from sibling tools like google_calendar_list_events. It does not explicitly call out the sibling comparison, but the resource noun is unambiguous.
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?
No guidance on when to use this tool versus alternatives (e.g., list_events, free_busy) or what prerequisites exist. The scope clause hints at account filtering but does not say when the tool should be selected.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.