calendly-mcp

calendly_list_available_slots

List available time slots for a Calendly event type between two dates (max 7 days). Returns UTC times for scheduling.

Instructions

Lista os horários disponíveis para um tipo de evento em um intervalo de datas. Máximo 7 dias por chamada. Retorna horários em UTC.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "event_type_uri": "<event_type_uri>",
      "start_date": "<start_date>",
      "end_date": "<end_date>"
    },
    "name": "calendly_list_available_slots"
  }
}

Input Schema

Name	Required	Description
`event_type_uri`	Yes	URI completa do tipo de evento (obtida via calendly_list_event_types)
`start_date`	Yes	Data de início no formato YYYY-MM-DD (fuso horário de Brasília BRT, UTC-3)
`end_date`	Yes	Data de fim no formato YYYY-MM-DD. Máximo 7 dias após start_date.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0May 28, 2026

TDQS

A3.7/5.0

Behavior3/5

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

No annotations were provided, so the description must carry the full burden. It adds the behavior of a 7-day maximum and UTC output, but this information partially duplicates the schema. It omits whether the operation is read-only, authentication needs, or result structure.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is extremely concise: two sentences, front-loaded with purpose, and every word adds value. No unnecessary information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

While it covers the core functionality and a key constraint, it lacks details about output format (e.g., list of start times or intervals) and error behavior. Without an output schema, the description should provide more context about the return value.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema descriptions cover 100% of parameters, so the tool description adds no new parameter-level insights. It only reiterates the 7-day limit already present in the end_date schema description.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it lists available slots for a given event type in a date range, with a maximum 7-day window and UTC return. It is distinct from sibling tools like calendly_schedule, which creates events, and calendly_get_event, which retrieves a specific event.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage when checking availability, but does not explicitly state when to use this tool versus alternatives. No when-not-to-use or prerequisite information is provided.

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

Deploy Server