canvas_discussions

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds value by disclosing the returned fields and the title-only nature of search filtering, but says nothing about pagination behavior or ordering despite the schema exposing a page parameter.

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, front-loaded with the core action and scope, followed by the disambiguation pointer. No redundant restatement of the tool name or schema content.

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 five-parameter read tool with no output schema, the description covers purpose, scope, return fields, filtering semantics and the key alternative. Only pagination and ordering behavior remain unstated, which is a minor gap given the page parameter's own schema description.

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%, so the baseline is 3. The description contributes one clarification — that search_term matches against the title rather than a generic 'name' — but adds no detail on context_type/context_id pairing or how the page cursor is obtained.

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?

States a specific verb and resource ('List discussion topics') plus scope ('in a course or group') and enumerates the return fields (titles, authors, dates, reply counts). It also explicitly distinguishes itself from the canvas_announcements sibling, so an agent can route without opening either schema.

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?

Clear usage context: use this for discussion topics in a course or group, and use canvas_announcements for announcements. It stops short of naming the closest siblings (canvas_discussion, canvas_discussion_entries) as follow-ups for reading thread contents, so there is still some inference required.

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