Read an inbox thread

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 covered. The description adds a specific behavioral detail: 'Does not mark it as read (stays read-only)', which explicitly guarantees that the tool does not alter conversation read state. This goes beyond the generic annotation and provides useful context for an agent.

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 two concise sentences that front-load the primary action ('Read one inbox conversation thread') and then add a clarifying behavior. There is no filler or redundant content, and every word contributes to understanding the tool's purpose.

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?

For a simple read-only tool with one parameter, no output schema, and annotations covering safety and idempotency, the description is complete. It conveys the core action, the read-only guarantee, and implicitly differentiates from list operations. No additional information is needed for correct invocation.

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?

The input schema already provides 100% coverage with a description for conversationId ('Canvas numeric id'), which is sufficient baseline. The tool description does not add additional meaning about the parameter's format, constraints, or usage beyond what the schema states. No extra context is needed for this single-parameter tool.

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 states a specific verb ('Read') and a specific resource ('one inbox conversation thread'), which clearly distinguishes it from sibling tools like canvas_list_conversations (which lists threads) and canvas_get_unread_message_count. It also adds precision by clarifying the scope ('one') and the read-only nature.

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 usage context is implied through the name and description: to read a specific thread, as opposed to listing all threads. However, there is no explicit mention of when to use this tool versus alternatives like canvas_list_conversations, nor any stated exclusions. The description implies usage but does not provide clear routing guidance.

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