ebill_download_bill

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

With no annotations, the description carries the burden of disclosing behavior. It clearly states the primary action (downloading a PDF to a path), but does not mention file overwrite behavior, whether directories are created, or any side effects. This is adequate for a simple operation but lacks deeper context.

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 a single, focused sentence with no unnecessary words. It front-loads the core action and destination, making it immediately scannable and easy to understand.

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 simple two-parameter download tool, the description is largely complete. It lacks context about what happens after the download (e.g., return value) and does not mention edge cases like overwriting, but given the lack of an output schema and the simplicity of the operation, it covers most essentials.

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 50%: output_path has a description ('absolute path to write to'), while bill_id has none. The description reinforces the output_path purpose but adds no detail about bill_id format or identifier semantics. It provides minimal added meaning beyond 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 description 'Download one bill PDF to an absolute output_path' uses a specific verb and resource, stating exactly what the tool does. It distinguishes from siblings like 'ebill_download_all' by emphasizing 'one' bill and from 'ebill_get_bill' by indicating a PDF file download to a path.

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 no guidance on when to use this tool versus alternatives, such as 'ebill_get_bill' for viewing or 'ebill_download_all' for bulk downloads. There is no explicit mention of exclusions or preferred use cases, leaving the agent to infer from the name alone.

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