US Government Open Data MCP

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

No annotations are provided, so the description carries full burden. It states a read operation ('Get') but doesn't disclose any behavioral traits like authentication requirements, rate limits, error conditions, or whether it's idempotent. The description is minimal and adds no behavioral context beyond the basic operation.

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 a single, efficient sentence that front-loads the core purpose and lists the specific metadata fields. Every word earns its place with zero waste or 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 read tool with one parameter and no output schema, the description adequately covers the purpose and output fields. However, without annotations or output schema, it lacks details on return format, error handling, or any behavioral constraints, making it minimally complete but with clear gaps.

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?

The schema has 100% description coverage, with the single parameter 'series_id' well-documented in the schema. The description adds no parameter-specific information beyond what's in the schema, but with only one parameter and high schema coverage, the baseline is 3. The description's clarity about what metadata is returned provides some additional context, justifying a 4.

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 ('Get metadata') and resource ('for a FRED series'), listing the exact metadata fields returned (title, units, frequency, range, notes). It distinguishes from sibling tools like 'fred_series_data' (which likely returns actual data values) by focusing on metadata.

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 implies usage when metadata is needed, but provides no explicit guidance on when to use this versus alternatives like 'fred_search' (for finding series) or 'fred_series_data' (for data values). It lacks any 'when-not' or prerequisite information.

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