Canvas LMS MCP Server

Create Assignment Override

create_assignment_override

Destructive

Instructions

Create a due-date / availability override for a specific assignment, targeting a set of students, a course section, or a group. Exactly one of student_ids, course_section_id, or group_id must be provided. At least one date field (due_at, unlock_at, lock_at) should be provided; omit a date field to leave the corresponding date unchanged for the override target. Dates must be ISO 8601 strings (e.g. "2026-09-15T23:59:00Z"). Canvas returns a 422 if a student-set override already exists for the same students on this assignment — use list_assignment_overrides to audit first. Provide student_ids as real Canvas user IDs. If CANVAS_PSEUDONYMIZE_STUDENTS is enabled, call resolve_pseudonym first to resolve pseudonyms to real user IDs.

Input Schema

Name	Required	Description
`title`	No	Human-readable label for this override (e.g. "Disability accommodation — Jane D").
`due_at`	No	New due date in ISO 8601 format. Pass null to remove the due date for this target.
`lock_at`	No	Availability close date in ISO 8601 format. Pass null to remove.
`group_id`	No	ID of the group to override. Mutually exclusive with student_ids and course_section_id.
`course_id`	Yes	Canvas course ID
`unlock_at`	No	Availability open date in ISO 8601 format. Pass null to remove.
`student_ids`	No	Real Canvas user IDs to grant the override to. Mutually exclusive with course_section_id and group_id.
`assignment_id`	Yes	Canvas assignment ID
`course_section_id`	No	ID of the course section to override. Mutually exclusive with student_ids and group_id.

Schema Changelog

Changes observed during successful MCP inspections.

Changed20 schema fields changedv1.18.15Oct 14, 2026

addedInput schema / properties / assignment_id / anyOf

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

removedInput schema / properties / assignment_id / exclusiveMinimum
```
Removed value: -0
```
removedInput schema / properties / assignment_id / maximum
```
Removed value: -9007199254740991
```
removedInput schema / properties / assignment_id / type
```
Removed value: -"integer"
```

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 / exclusiveMinimum
```
Removed value: -0
```
removedInput schema / properties / course_id / maximum
```
Removed value: -9007199254740991
```
removedInput schema / properties / course_id / type
```
Removed value: -"integer"
```

addedInput schema / properties / course_section_id / anyOf

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

removedInput schema / properties / course_section_id / exclusiveMinimum
```
Removed value: -0
```
removedInput schema / properties / course_section_id / maximum
```
Removed value: -9007199254740991
```
removedInput schema / properties / course_section_id / type
```
Removed value: -"integer"
```

addedInput schema / properties / group_id / anyOf

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

removedInput schema / properties / group_id / exclusiveMinimum
```
Removed value: -0
```
removedInput schema / properties / group_id / maximum
```
Removed value: -9007199254740991
```
removedInput schema / properties / group_id / type
```
Removed value: -"integer"
```

addedInput schema / properties / student_ids / items / anyOf

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

removedInput schema / properties / student_ids / items / exclusiveMinimum
```
Removed value: -0
```
removedInput schema / properties / student_ids / items / maximum
```
Removed value: -9007199254740991
```
removedInput schema / properties / student_ids / items / type
```
Removed value: -"integer"
```

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"

Changed6 schema fields changedv1.18.8Sep 2, 2026

removedInput schema / properties / due_at / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedInput schema / properties / due_at / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedInput schema / properties / lock_at / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedInput schema / properties / lock_at / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedInput schema / properties / unlock_at / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedInput schema / properties / unlock_at / type
```
Added value: +[
+  "string",
+  "null"
+]
```

Addedv1.18.3Jul 24, 2026

TDQS

A4.5/5.0

Behavior4/5

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

Annotations supply destructiveHint=true and openWorldHint=true, and the description adds real behavioral context beyond them: a 422 error when a student-set override already exists, the partial-update semantics ('omit a date field to leave the corresponding date unchanged'), and the pseudonymization prerequisite. It stops short of warning that an existing override for the same target may be replaced or how to undo.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with purpose, then constraints, then sequencing, then format — a logical order with little waste. It is fairly dense with rules, but each sentence carries distinct, non-redundant information.

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?

For a 9-parameter mutation with no output schema and only two annotations, the description covers the key constraints, error behavior, and prerequisites an agent needs to invoke it correctly. It omits permission requirements and expected response shape, which would round it out.

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 coverage is 100%, so the per-parameter descriptions already carry most semantics. The description still reinforces value by surfacing the tool-level 'exactly one target' and 'at least one date' rules plus the ISO 8601 example format in a single place, though it does not add new per-parameter detail.

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?

States a specific verb and resource — 'Create a due-date / availability override for a specific assignment' — and immediately enumerates the three override target types. This clearly distinguishes it from sibling tools like list_assignment_overrides and set_student_assignment_dates.

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?

Gives explicit preconditions: exactly one of student_ids/course_section_id/group_id, at least one date field, ISO 8601 formatting, auditing via list_assignment_overrides to avoid a 422, and calling resolve_pseudonym first when pseudonymization is on. This is a near-complete decision and sequencing guide.

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

Deploy Server

Create Assignment Override

Instructions

Input Schema

Schema Changelog

TDQS

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