Deferno MCP Server

delete_event_occurrence

Clear an event occurrence row entirely using event ID and date to undo a prior mark.

Instructions

Clear an event occurrence row entirely (undo a prior mark).

event_id accepts any reference form — UUID, sequence shorthand (#123, personal-org only), canonical ref (acme-123), or app URL — and is resolved to a UUID before the clear.

date is YYYY-MM-DD. Returns {"ok": true} on success.

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_id": "<event_id>",
      "date": "<date>"
    },
    "name": "delete_event_occurrence"
  }
}

Input Schema

Name	Required	Description	Default
`event_id`	Yes
`date`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jun 11, 2026

TDQS

A4.3/5.0

Behavior3/5

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

With no annotations, the description should fully disclose behavioral traits. It explains return value and event_id resolution, but does not explicitly state that the deletion is permanent or destructive, nor mention any side effects or authorization needs.

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 plus brief parameter clarifications, front-loaded with the main purpose, and every word adds value. No unnecessary text.

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

Completeness4/5

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

Given the tool's simplicity and presence of output schema (implied), the description covers parameters and return value well. It lacks mention of error conditions or side effects, but is otherwise adequate for a straightforward delete operation.

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

Parameters5/5

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

Although schema description coverage is 0%, the description adds substantial meaning: it explains accepted reference forms for event_id and date format, which the schema lacks. This compensates fully for the schema's omissions.

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 the tool clears an event occurrence row, using specific verbs like 'clear' and 'undo a prior mark', which distinguishes it from sibling tools like 'delete_event' and 'set_event_occurrence'.

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

Usage Guidelines4/5

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

The description implies usage for undoing a prior mark, but does not explicitly list when to use versus alternatives or when not to use, though context from sibling names provides differentiation.

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

Deploy Server