msgraph-mcp

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get_attachments

Retrieve attachments from a Microsoft Graph message. List all attachment metadata or download a specific attachment as base64.

Instructions

Get attachments for a message. Without attachment_id: list all metadata. With attachment_id: download that attachment (base64 if under 1.5 MB).

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": "get_attachments"
  }
}

Input Schema

Name	Required	Description	Default
`account_id`	No
`message_id`	Yes
`attachment_id`	No

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jul 29, 2026

TDQS

A4/5.0

Behavior4/5

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

With no annotations, the description carries the full burden. It discloses two distinct behaviors (list vs. download) and notes the base64 encoding threshold (under 1.5 MB). However, it does not clarify what happens for attachments over 1.5 MB or other potential error conditions, leaving minor gaps.

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 that front-load the purpose and then provide necessary conditional details. Every word adds value with no redundancy.

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 that an output schema exists (so return details are not needed), and the tool's behavior is relatively simple, the description covers the essential modes. However, it could briefly mention authentication prerequisites or handling of multiple attachments for completeness.

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 0%, so the description must compensate. It explains the role of message_id (implied) and attachment_id (controls behavior), but does not mention account_id at all, which is an optional parameter. Thus, it adds meaning for two of three parameters.

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's purpose: getting attachments for a message. It further distinguishes the two modes based on whether an attachment_id is provided, making the behavior explicit and differentiating it from sibling tools like add_attachment_to_draft.

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 provides implicit guidance on when to list metadata versus download an attachment, but it does not explicitly compare usage with alternatives (e.g., list_messages, add_attachment_to_draft) or mention when not to use this tool.

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