@mnicole-dev/calcom-mcp-server

reschedule-booking

Reschedule an existing booking to a new start time by providing the booking UID and desired ISO 8601 datetime. Optionally include a reason for the change.

Instructions

Reschedule a booking to a new start time.

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": {
      "bookingUid": "<bookingUid>",
      "start": "<start>"
    },
    "name": "reschedule-booking"
  }
}

Input Schema

Name	Required	Description
`start`	Yes	New ISO 8601 start datetime
`bookingUid`	Yes	The booking UID to reschedule
`reschedulingReason`	No	Reason for rescheduling

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Aug 30, 2026

TDQS

B3.3/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It communicates that the operation is a mutation but does not explain side effects, such as whether the old booking slot is released, whether availability is validated, whether notifications are sent, or whether rescheduling can be reversed.

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 a single, front-loaded sentence with no filler or repetition. Every word contributes to the core meaning, making it easy for an agent to parse quickly.

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?

For a three-parameter tool with no output schema and no annotations, the description is minimally adequate but leaves gaps. It does not mention expected return value, error conditions, or behavioral constraints, though the schema and clear verb cover the essential mechanics of the operation.

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?

The input schema already describes all three parameters with 100% coverage, so the baseline is 3. The description adds minimal semantic value: it confirms 'start' means the new start time, but it does not elaborate on bookingUid or reschedulingReason beyond what the schema already states.

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 uses a specific verb and resource: 'Reschedule a booking to a new start time.' This clearly distinguishes the tool from siblings like create-booking, cancel-booking, and confirm-booking by stating exactly what action is performed and on what object.

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

Usage Guidelines2/5

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

The description provides no guidance on when to use this tool versus alternatives such as canceling and recreating a booking, nor does it mention any preconditions like availability checks. It only states the basic purpose, so the agent must infer usage entirely from the tool name and context.

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