nylas_list_calendarsList calendars for the connected account (each has a calendar_id used by the events tools). Nylas v3: GET /v3/grants/{grant_id}/calendars.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Max calendars to return. | |
| grant_id | No | Connected-account grant id. Overrides NYLAS_GRANT_ID for this call. | |
| page_token | No | Pagination cursor (next_cursor from a prior page). |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true. Description adds the API endpoint and contextual note about calendar_id, which is useful but not required. No additional behavioral traits (e.g., pagination behavior) beyond schema.
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?
Two sentences, front-loaded with purpose, zero waste. Every sentence adds value.
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 no output schema, description provides adequate context for a list tool with fully described parameters. Could mention return structure (e.g., calendar objects with id/name) but not necessary for selection.
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 baseline is 3. Description does not add extra meaning beyond what the schema provides for the parameters. It mentions calendar_id context but not as a parameter.
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?
Specific verb 'List', resource 'calendars', and scope 'for the connected account'. Clearly distinguishes from sibling tools like nylas_list_events or nylas_get_calendar by focusing on calendars and noting the calendar_id is used by events 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?
States the purpose and links to events tools (calendar_id). Provides clear context for when to use, but does not explicitly state when not to use or name alternatives like nylas_get_calendar.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool targets a distinct resource and action: create vs list vs get for specific entities like draft, event, calendar, contact, grant, message, folder. There is no overlap, as even similar verbs like 'list' are paired with unique nouns. Agents can easily select the correct tool.
All tool names follow a uniform 'nylas_verb_noun' pattern using snake_case, with clear and predictable verbs (create, get, list, send) and nouns (draft, event, calendar, etc.). The naming is fully consistent across all 15 tools.
With 15 tools, the set is well-scoped for a Nylas integration covering email, calendar, and contacts. Each tool serves a clear purpose without redundancy, and the count falls comfortably within the ideal range of 3-15 tools.
The tool set covers reading and limited creation (drafts, events) but lacks update and delete operations for all entities, as well as create for contacts. This leaves notable gaps for full lifecycle management, though core workflows like listing and fetching are present.