Canvas LMS MCP Server

Download File

download_file

Read-only

Download the content of a Canvas file by ID. Text files (plain text, HTML, JSON, XML, JavaScript) are returned as readable text. Binary files (images, PDFs, etc.) are returned as base64-encoded data. Files larger than 10 MB are refused.

Instructions

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": {
      "file_id": "<file_id>"
    },
    "name": "download_file"
  }
}

Input Schema

Name	Required	Description	Default
`file_id`	Yes	The Canvas file ID
`course_id`	No	Optional Canvas course ID to scope the file lookup

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedv1.18.15Oct 14, 2026

addedInput schema / properties / course_id / anyOf

Added value: +[
+  {
+    "exclusiveMinimum": 0,
+    "maximum": 9007199254740991,
+    "type": "integer"
+  },
+  {
+    "pattern": "^[1-9][0-9]{0,18}$",
+    "type": "string"
+  }
+]

removedInput schema / properties / course_id / type
```
Removed value: -"number"
```

addedInput schema / properties / file_id / anyOf

Added value: +[
+  {
+    "exclusiveMinimum": 0,
+    "maximum": 9007199254740991,
+    "type": "integer"
+  },
+  {
+    "pattern": "^[1-9][0-9]{0,18}$",
+    "type": "string"
+  }
+]

removedInput schema / properties / file_id / type
```
Removed value: -"number"
```

Changed1 schema field changedv1.18.11Sep 10, 2026

changedInput schema / $schema

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

First observedv1.18.0May 25, 2026

TDQS

A3.6/5.0

Behavior4/5

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds valuable behavioral details beyond annotations: text files return readable text, binary files return base64, and files larger than 10 MB are refused. This meaningfully informs the agent about return behavior and limits.

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 tightly written sentences with zero waste. The most important information (what it downloads) is front-loaded, followed by return formats and the size limit, all earning their place.

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?

With no output schema, the description carries the burden of explaining return values and does so by distinguishing text versus base64 binary returns. It also states a hard 10 MB limit. It does not mention error conditions or the optional course_id scoping, but these are minor gaps for a read-only download tool with fully documented parameters.

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 documents file_id and course_id fully. The description adds no parameter-level detail (e.g., course_id scoping), so baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb (Download) and resource (Canvas file content by ID), making it clear what the tool does. It does not explicitly differentiate from sibling tools like get_file or list_files, so it falls short of a 5.

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 offers no guidance on when to use this tool versus alternatives such as get_file (metadata) or list_files (listing), nor does it state prerequisites or exclusions. It only describes output behavior, not usage context.

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

Deploy Server