Skip to main content
Glama
ni-c

carddav-mcp

by ni-c
OverviewSchemaSourceRelated ServersDiscussionsAdmin
TypeScript
Remote

What changed in an address book

list_changes
Read-onlyIdempotent

Get contacts added, changed, or deleted since a sync token. Call without a token for the initial snapshot and token, then pass it later for incremental updates.

Instructions

Cards created, changed or deleted since a sync token, using RFC 6578. Call it once without a token to get the current token, then again later with it. Not every server implements this — get_server_info reports whether this one does.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
limitNoHow many entries to return. Defaults to CARDDAV_MAX_CONTACTS, at most 500.
sync_tokenNoThe token from a previous call. Left out, this returns the current token and every card, which is the initial sync.
address_bookYesAn address book id from list_address_books — its collection path. A full URL or the final path segment work too.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
countYesEntries in this answer, after any limit was applied.
notesNo
totalYesEntries the server reported, before the limit.
changedYes
removedYesIds of cards that are gone.
sync_tokenNoPass this to the next call.
address_bookYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changedv0.1.3
    • changedInput schema / properties / sync_token / maxLength
      Previous value: -2048New value: +512
  2. First observedv0.1.0

TDQS

A4.5/5.0
Behavior4/5

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

Annotations already cover the read-only, idempotent, non-destructive profile. The description adds useful behavioral context beyond that: the two-step token flow and the server-support caveat. It does not describe pagination or invalid-token behavior, but the presence of a limit parameter and output schema mitigates this.

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?

Three sentences with no filler. The core behavior, usage pattern, and important server-support caveat are all front-loaded and stated efficiently.

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

Completeness5/5

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

Given the full parameter schema, output schema, and annotations, the description covers the essential context: what the tool does, how to use it across calls, and when it may not be available. Nothing critical is missing for an agent to invoke it correctly.

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 description coverage is 100%, so the schema already fully documents all three parameters. The description adds context around the sync_token flow but does not provide new parameter-level meaning beyond what the schema 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 clearly states what the tool returns: cards created, changed, or deleted since a sync token, using RFC 6578. The title 'What changed in an address book' reinforces this, and the focus on changed cards distinguishes it from sibling tools like list_contacts and search_contacts.

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

Usage Guidelines5/5

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

It gives an explicit usage pattern: call once without a token to get the current token, then call again later with it. It also tells the agent when not to rely on it by noting that not every server supports the feature and pointing to get_server_info as the check.

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

Deploy Server

Other Tools