List Canvas inbox messages

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds that it returns sender, course, preview, and read state, which is useful but does not disclose pagination behavior or rate limits. Given good annotations, the bar is lower, and the description adds moderate value.

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?

Two sentences with no wasted words. The first sentence states the core function and output fields; the second provides actionable usage guidance. Every sentence earns its place.

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 only 2 optional parameters, no output schema (so the description doesn't need to document return fields beyond what it states), and strong annotations, this description is complete enough. It covers purpose, output fields, and usage guidance for the key filter. Could mention pagination or limit defaults but not strictly necessary for this simple tool.

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 coverage is 100%, so the schema already documents both parameters (limit, scope) with descriptions and enums. The description adds marginal meaning by suggesting a common scope value ('unread'), but this is a minor enhancement. Baseline 3 is appropriate.

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 uses a specific verb ('List') and resource ('Canvas inbox messages'), and clarifies what the messages contain (sender, course, preview, read state). It distinguishes from siblings like canvas_list_announcements or canvas_list_discussions by explicitly naming the 'Canvas inbox' context.

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 explicit usage guidance for the scope parameter ('Use scope='unread' for just unread messages'), which helps the agent decide when to filter. However, it doesn't mention when not to use this tool or compare it directly to siblings like canvas_get_conversation for reading individual messages.

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