canvas_get_discussion

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

With no annotations, the description carries the full burden and does meaningful work: it discloses the return shape (full reply thread, plain text), a FERPA/attribution constraint, and payload bounding via max_chars. It omits auth/permission requirements and failure modes, which keeps it short of a 5.

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?

Purpose is front-loaded in the first sentence, followed by a compact compliance/usage note and a tight Args block. Every line adds information (format, constraint, defaults) with no filler.

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?

An output schema exists, so return values need not be re-explained; instead the description covers the format, privacy handling, default resolution, and payload bounding. For a 3-param read tool with no annotations, nothing essential is missing.

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 0%, so the description must compensate and does: topic_id is the numeric discussion topic id, course_id defaults to CANVAS_DEFAULT_COURSE_ID, and max_chars bounds the payload with 0 meaning the server default. All three parameters gain semantics beyond their bare types.

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 ('Get a discussion topic with its full reply thread as plain text'), clearly distinguishing it from sibling listers like canvas_list_discussions and bulk exporters like canvas_download_submissions. An agent can tell what it fetches and in what shape without opening the 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?

Explicitly scopes usage ('summarise a week's discussion, not to bulk-export it'), giving both a use case and an exclusion. It does not name the specific alternative tool (e.g. canvas_list_discussions or a bulk export path), so routing is implied rather than explicit.

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