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

Beyond the annotations (readOnlyHint, idempotentHint), the description adds critical context: 'Patent and exclusivity dates are FDA listings, not a legal conclusion about enforceability or actual generic entry.' This warns users about data limitations and legal implications, which annotations do not cover.

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?

Two sentences with no redundancy. The first sentence states the core purpose, and the second provides an essential caveat. Every sentence adds value without waste.

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 covers what data is retrieved (product, patent, exclusivity rows) and the scope (single application). An output schema exists, so return values are defined. A mention of any limits or error handling could improve completeness, but it is sufficient.

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 a clear description for the only parameter 'application_number'. The tool description adds no extra parameter information beyond the schema, so a baseline of 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 uses a specific verb 'Retrieve' and clearly defines the resource: 'all FDA Orange Book product, patent, and exclusivity rows for one NDA or ANDA application'. This distinguishes it from sibling tools like 'orange_book_product_search' (broader search) and 'orange_book_patent_expirations' (expiration-focused).

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 states the tool is for 'one NDA or ANDA application', implying it is for single-application detail rather than bulk queries. However, it does not explicitly mention when not to use it or provide alternatives from the sibling list, such as the expiration tools for aggregate views.

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