download_course_files

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

With no annotations, the description carries the burden and does real work: it discloses that download_path does not mutate the saved setting ("never changes it"), that account defaults to the active account, and that folder layout depends on flat. It does not cover overwrite behavior for existing files, directory creation, or failure modes for a write-to-disk operation.

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 one-line purpose is front-loaded and the Args block is terse with no filler. The raw docstring format is slightly less scannable than prose, but no sentence is wasted.

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 six-parameter filesystem-writing tool, the definition covers selection, location, layout, and account routing, and an output schema exists so return values need no explanation. The remaining gap is file-collision and path-permission behavior, which an agent would want before calling it on a populated directory.

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 it does: every one of the six parameters gets meaning, including accepted date syntax for since (YYYY-MM-DD or "7d"), the default-inheritance semantics of download_path and account, and the layout consequence of flat. This is substantially more than the bare types in the schema.

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 opening line names a specific verb and resource ("Download files from a Canvas course") and immediately bounds scope with "all of them, or a selection." It also routes to the sibling list_course_files for obtaining file ids, so an agent can tell it apart from the listing tool 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?

Usage context is clear: bulk download by default, narrowed via file_ids or since, and file_ids are explicitly sourced from list_course_files. There is no explicit when-not guidance (e.g., use get_course_page for single pages, or list_course_files to preview before downloading), which keeps it short of a 5.

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