Read a discussion thread

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the behavioral safety profile is covered. The description adds content details (threaded view, reply bodies) but no further behavioral traits such as pagination, rate limits, or return format specifics. This is consistent and adds modest value beyond the annotations.

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 that directly states the tool's output and scope without any redundant phrasing. It is appropriately concise for a simple read operation, with no filler or unnecessary detail.

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 two-parameter read-only tool with no output schema, the description provides adequate context about the return content (full thread with reply bodies). It could be more explicit about other response elements (e.g., author info, attachments), but for a straightforward retrieval tool this is sufficient. The annotations cover safety and open-world behavior, so the description is reasonably complete.

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?

Both parameters (courseId and topicId) have full schema descriptions, giving 100% coverage. The tool description adds no additional parameter details, so it does not exceed the schema baseline. Since the schema already documents parameter meaning, a 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 clearly states a specific verb and resource: it provides a 'full threaded view of a discussion topic, including reply bodies.' This distinguishes it from sibling tools like canvas_list_discussions, which list topics rather than return thread content. The meaning is unambiguous and ties directly to the tool name and title.

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 implies usage for viewing a specific discussion's full thread, but it does not explicitly state when to use this tool versus alternatives like canvas_list_discussions. No exclusions or alternative conditions are mentioned, leaving the agent to infer from the sibling list. This is adequate but lacks explicit routing.

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