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

Annotations already indicate readOnlyHint false and destructiveHint false, establishing this as a non-readonly, non-destructive write operation. The description adds meaningful behavioral context by specifying that the course is placed 'at the end' of the collection, which is not inherent in the annotations. It does not contradict the annotations and provides additional behavioral detail beyond them.

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, concise sentence that clearly communicates the action and its placement. Every word earns its place, with no redundancy or filler, making it optimally front-loaded and easy to parse.

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 two-parameter mutation tool with an output schema present, the description adequately covers the core action. It does not explain return values (unnecessary given the output schema), but it omits explicit mention of constraints like uniqueness (though that is in the schema). Overall, it is complete enough for an agent to take action, though adding a note about duplicate behavior would push it to a 5.

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 schema provides 100% description coverage for both parameters, with detailed notes on id (collection id from list_collections/create_collection) and courseId (course in workspace, appended at end, can appear only once). The description itself adds no further parameter meaning beyond what the schema already conveys, so it meets the baseline but does not exceed it.

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 'Adds a course to the end of a collection' clearly states a specific verb (adds), resource (course to collection), and the particular placement ('end'). It distinguishes from siblings like remove_course_from_collection and move_course_in_collection by indicating the action is addition at the end, not removal or reordering.

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 does not explicitly state when to use this tool versus alternatives such as move_course_in_collection or remove_course_from_collection. It relies on the tool name and schema hints (e.g., 'as returned by list_collections or create_collection') to convey context, but no direct usage guidance or exclusions are provided.

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