canvas_download_file

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

Annotations declare destructiveHint=true, readOnlyHint=false and openWorldHint=true, so the write/network profile is already covered. The description usefully adds the validation rules (only configured Canvas host URLs accepted; destination confined to CANVAS_OUTPUT_DIR), but never explains the destructive aspect or mentions the `overwrite` parameter at all, leaving the reason for the destructive hint unexplained.

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, purpose front-loaded, with constraints in tight parentheticals. The density is slightly heavy but nearly every clause carries necessary constraint information, so there is little waste.

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?

With no output schema, the absence of return-value information is acceptable, and the security constraints are covered. But for a file-writing tool flagged destructive, the missing explanation of `overwrite` semantics and of what gets destroyed leaves a real gap for correct invocation.

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 coverage is 67%, and the description mirrors the schema for `url` and `destinationPath`, adding the env-var name and default directory plus path-resolution behavior. However `overwrite` is undocumented in both the schema and the description, so the description does not compensate for the coverage gap.

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 ('Download a Canvas file to disk') and immediately differentiates itself from the sibling canvas_list_course_files by naming it as the source of the `url`. An agent can tell this is the write-side counterpart to 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?

Gives clear usage context: the `url` must come from canvas_list_course_files, and `destinationPath` must live in the download directory. It does not explicitly state when not to use it (e.g. alternatives for bulk download or non-Canvas URLs), so it falls just short of full when/when-not guidance.

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