canvas_update_assignment

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. 'Update an existing assignment' implies a mutation operation, but it doesn't describe what happens if fields are omitted (partial vs. full update), whether changes are reversible, permission requirements, rate limits, or error conditions. This leaves significant gaps for an agent to understand the tool's behavior beyond basic functionality.

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

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

The description is a single, efficient sentence with zero wasted words. It's front-loaded with the core action and resource, making it easy to parse quickly. No unnecessary details or fluff are included, which is ideal for conciseness.

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

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

Given the complexity of a mutation tool with 7 parameters, no annotations, and no output schema, the description is incomplete. It lacks behavioral context (e.g., update semantics, error handling), usage guidelines, and output details. While the schema covers parameters well, the description fails to provide the broader context needed for safe and effective tool invocation by an agent.

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

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

Schema description coverage is 100%, with all parameters clearly documented in the input schema (e.g., assignment_id, course_id, description). The description adds no additional parameter semantics beyond what the schema provides, such as format examples or constraints. However, since the schema is comprehensive, a baseline score of 3 is appropriate as the description doesn't need to compensate for gaps.

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

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

The description 'Update an existing assignment' clearly states the action (update) and resource (assignment), which is specific and unambiguous. However, it doesn't explicitly differentiate from sibling tools like canvas_update_course or canvas_update_user_profile, though the resource name makes the distinction obvious.

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

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

The description provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing course_id and assignment_id), when not to use it, or how it differs from related tools like canvas_create_assignment or canvas_get_assignment. The agent must infer usage from the tool name and parameters alone.

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