Outlook MCP Server

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mark_read

Mark a single Outlook message as read, or revert it to unread with is_read=false, to keep inbox status accurate. Use mark_messages_read when updating multiple messages.

Instructions

Mark one message read, or unread with is_read=false. Reversible. For several messages use mark_messages_read.

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": {
      "message_id": "<message_id>"
    },
    "name": "mark_read"
  }
}

Input Schema

Name	Required	Description	Default
`is_read`	No
`message_id`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 9, 2026

TDQS

A4.2/5.0

Behavior3/5

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

No annotations are supplied, so the description carries the full burden. It usefully declares the operation is reversible and that is_read=false flips the meaning, but it omits permission requirements, idempotency (what happens if the message is already read), and error behavior for invalid IDs. That is meaningful context yet not a full behavioral picture for a mutation tool.

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?

Two very short sentences with zero filler. The core action and its inverse lead, and the sibling routing follows immediately.

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?

The tool has only two parameters and an output schema, so return values need no explanation. Purpose, reversibility, and the bulk alternative are all covered; only edge-case behavior (missing message, already-in-target-state) is unaddressed.

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

Parameters4/5

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

Schema description coverage is 0%, so the description must compensate, and it does for the non-obvious parameter: is_read is explained as producing unread state when false. message_id is left implicit, but its meaning is self-evident from the field name and the stated scope of one message.

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 gives a specific verb and resource ("Mark one message read") and explicitly defines the inverse operation ("unread with is_read=false"). It also names the sibling mark_messages_read, so the agent can distinguish single-message from bulk behavior without opening either schema.

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?

It states an explicit routing rule: "For several messages use mark_messages_read." That covers the main selection ambiguity between this tool and its plural sibling. It stops short of stating preconditions, such as whether the message must be in the inbox or whether the operation errors on a nonexistent ID.

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