Download attachment

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

Annotations already declare readOnlyHint and destructiveHint, so the bar is lower. The description adds valuable context that content is NOT loaded into the conversation (safe for large files) and that it returns the saved file path and size, which is useful given the lack of an output schema. No contradiction found.

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?

Three sentences: purpose, return value/safety, and pointer to sibling tool. Each sentence earns its place and the key information is front-loaded. No redundancy.

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 tool with two well-documented parameters, the description covers purpose, return values, safety behavior, and how to obtain required IDs. The absence of an output schema is compensated by explicitly stating what the tool returns. This is fully adequate for an agent to select and invoke 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% with clear descriptions for both id and output_path. The description does not add meaning beyond the schema—it only restates the concept of saving to a local path. Baseline 3 is appropriate.

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 specific action (download an attachment's file content) and destination (save to a local path). It distinguishes from sibling tools by indicating that attachment IDs come from easybill_list_attachments, making the tool's role 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?

Provides clear context: the tool saves locally without loading content into the conversation, making it safe for large files. It also tells users to find attachment IDs via easybill_list_attachments. However, it does not explicitly compare against similar tools like get_attachment, so no explicit alternative/exclusion is given.

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