ed_download_resource

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

Annotations provide minimal safety context (readOnlyHint=false, destructiveHint=false), so the description adds value by mentioning a 50MB size limit and the link-type resource caveat. However, it does not disclose behaviors like file overwriting, network failure handling, or the exact local save behavior beyond the schema default, leaving some gaps.

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 two sentences, front-loaded with the action, and includes only essential details. Every sentence contributes value: what it does, where to get the resource_id, a constraint, and a size limit. No redundant information.

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 relatively simple tool with two parameters and no output schema, the description covers the key context: purpose, parameter source, default path, and a size limit. It does not explain the return value, but that is less critical in the absence of an output schema. The description is adequate for an agent to invoke the tool correctly in most scenarios.

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?

With 50% schema coverage, the description adds meaning by explicitly stating that resource_id comes from ed_list_resources and clarifying the default save path behavior (current directory + resource name and extension). This goes beyond the schema and helps the agent understand parameter provenance and defaulting.

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 clearly states the tool downloads Ed course resource files to a local destination, with a specific verb and resource. It also distinguishes from siblings by noting the source of resource_id and the limitation for link-type resources, making it unambiguous.

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 provides clear context on when to use the tool: when needing to download a file resource, with resource_id sourced from ed_list_resources. It also notes that link-type resources have no file to download, which serves as an exclusion criterion. It does not explicitly mention alternatives, but the platform-specific naming and instructions are sufficient.

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