epf_download_epf_file

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

Since no annotations are provided, the description carries the full burden of behavioral disclosure. It reveals a critical behavioral trait: bytes never enter the LLM context, and it streams to a specific directory (EPF_DOWNLOAD_DIR). This goes beyond a basic description and helps the agent understand side effects and limitations. However, it does not cover error handling, authentication requirements, or potential overwrite behavior.

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 with no wasted words. It front-loads the core action and result, then adds the critical behavioral note about bytes never entering context. Every sentence adds value.

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?

The description explains the primary purpose and the return metadata, but it omits how to obtain a valid fileId, whether authentication is required (given sibling epf_login), and what happens on error or missing file. With only one parameter and no output schema, the description should provide more contextual guidance 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 description coverage is 0%, so the description must compensate by explaining the parameter. The description does not mention 'fileId' at all, nor does it explain what it represents or how to obtain it. The only clue is the schema's pattern, which is technical. An agent would have to infer that fileId identifies the EPF file to download. This is a significant gap for a single-parameter tool.

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 action: 'Stream a binary EPF file to EPF_DOWNLOAD_DIR' and the outcome: return metadata only (path, content-type, byteLength, sha256). This is a specific verb and resource that distinguishes it from sibling tools like epf_download_list, which likely lists available files.

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, nor does it mention any prerequisites (e.g., being logged in via epf_login). It implies the tool is for downloading a specific file by ID, but there is no guidance on how to obtain a fileId or when to prefer other tools. No exclusions are given.

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