download_file

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

It goes well past the annotations: it explains why readOnlyHint is false (writes locally, not to Campus), confirms nothing is modified remotely, specifies no-overwrite behavior (relevant to idempotentHint=false), names the target directory and its env-var override, and states the return value (local path) despite having no output schema.

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?

One dense sentence that front-loads the action and destination before the caveats. It is efficient, though the nested parentheticals (formats, env var, default path) make it slightly harder to scan.

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 2-parameter download tool with no output schema, the description covers destination, overwrite policy, remote-side safety, and return value. It omits failure modes (invalid/expired URL, max size) but is otherwise sufficient to call correctly.

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 100%, so both url and filename are already documented, including accepted URL forms. The description adds only the destination-folder constraint already implied by the filename schema text, so baseline 3 applies.

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?

It uses a specific verb+resource ("Descarga un archivo del Campus") and defines the destination and side effect precisely. It does not, however, distinguish itself from nearby siblings such as read_file, open, get_pdf_page_image, or list_resources, which an agent could easily confuse with a download action.

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 is implied by the description: use this to pull a binary resource (PDF, presentation) onto local disk. There is no explicit statement of when to prefer read_file or get_pdf_page_image instead, and no mention of prerequisites such as an active session.

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