US Government Open Data MCP

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 effectively describes key behavioral traits: it's a search tool (implying read-only operation), provides specific query syntax examples, and mentions the ability to filter by marketing status. However, it doesn't disclose rate limits, authentication requirements, or pagination behavior beyond the 'limit' parameter.

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 efficiently structured: a clear purpose statement, two usage guidelines, and two example searches. Every sentence earns its place by providing essential information without redundancy. The information is front-loaded with the core purpose immediately stated.

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 tool's complexity (search with specialized query syntax), no annotations, and no output schema, the description does well by explaining the search domain, providing usage patterns, and showing examples. However, it doesn't describe the structure or content of search results, which would be helpful given the absence of an output schema.

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 100%, so the schema already documents both parameters thoroughly. The description adds value by providing concrete examples of search queries that demonstrate parameter usage in context, such as package_ndc searches and marketing status filters. This goes beyond the schema's generic examples.

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 tool's purpose: 'Search NDC SPL Data Elements — comprehensive drug product data.' It specifies the verb ('Search'), resource ('NDC SPL Data Elements'), and scope ('comprehensive drug product data'), distinguishing it from sibling tools like 'fda_drug_ndc' or 'fda_drug_labels' by focusing on structured product labeling data elements.

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 explicit guidance on when to use specific query patterns: 'Use '_missing_:marketing_end_date' for products still on market. Use '_exists_:marketing_end_date' for discontinued products.' It also includes example searches that illustrate practical applications, though it doesn't explicitly name alternative tools for different types of FDA data queries.

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