download_expense_receipt_image

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does detail the return format (base64 image data, content type, metadata) and the thumbnail default, which is useful. However, it doesn't mention that this is a read-only operation, any required permissions, or potential failure modes, leaving some important behavior undisclosed.

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 well-organized with a front-loaded purpose sentence followed by structured Args and Returns sections. It is concise and stays on topic, though the Returns section may partially duplicate what an output schema already provides.

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?

Given the simple nature of the tool (two parameters, one required, output schema present), the description covers all essential aspects: purpose, parameter meanings, and return value. It lacks explicit usage and edge-case behavior, but for this complexity level the completeness is strong.

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%, but the description fully compensates by clearly explaining both parameters: expense_id as the expense identifier and thumbnail as a boolean flag with its default value. This gives an agent everything needed to fill the parameters correctly.

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 opens with a clear, specific verb and resource: 'Download an expense receipt image from the backend API.' This distinctly separates it from the get_* summary tools and the save_expense_receipt_image sibling, making the tool's purpose immediately identifiable.

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 usage context is implied by the verb 'download' versus the 'save' sibling, but no explicit guidance is given about when to choose this tool over alternatives like get_expense_by_id or save_expense_receipt_image. There are no exclusions or conditions stated, so an agent must infer usage from the name and description alone.

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