AI-Process Credit Card

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

With no annotations, the description carries the full burden and does so well. It discloses async polling with 202 + Location, required IsAsync=true, conditional omission of CustomFieldKeys, and the .png extension fallback. This is substantial behavioral transparency.

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 dense and front-loaded with purpose; every clause conveys required information. It is somewhat run-on, but economical for the amount of technical detail provided.

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 tool with no annotations and no output schema, the description covers the endpoint, async semantics, file type constraints, naming behavior, and result file. This is sufficient for an agent to invoke it correctly, with only the minor omission of output_dir.

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?

Despite 0% schema coverage, the description details pdf_file_path accepted file types and Base64 encoding, doc_name defaults and extension behavior, and custom_field_keys conditional inclusion/PascalCase. The only omitted parameter is output_dir, so this is not a perfect score.

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?

Description opens with a specific verb and resource: 'extract structured data from a credit card image/PDF', and names the PDF4me endpoint. This clearly differentiates it from sibling tools like process_receipt and process_invoice.

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?

It defines the exact input domain (credit card image/PDF) and conditions for custom_field_keys, giving clear context for when to use the tool. It does not explicitly mention alternative tools or when not to use it, so it misses a 5.

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