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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive. The description adds valuable context: it is BEA's official lagged percent-change series, requires no math, and includes a source URL. No contradictions with annotations.

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?

Well-structured into paragraphs for purpose, usage, exclusions, and return value. Each sentence earns its place, and the example return object is compact yet informative. Nothing is redundant.

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?

Despite no output schema, the description provides a full structuredContent example with all field names and sample values, plus source attribution. For a zero-parameter read tool, this is complete and self-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?

The tool has zero parameters and the description confirms 'Args: none.' With no parameters to document, the baseline of 4 applies, and the description appropriately notes the absence of arguments.

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 it returns the latest U.S. real GDP growth rate as annualized quarter-over-quarter, plus prior quarters for trend context. It distinguishes itself from sibling macro tools by explicitly excluding dollar levels and expenditure-component details.

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?

Provides explicit 'When to use' and 'When NOT to use' sections with concrete use cases (growth pace, recession-risk context) and exclusions (dollar levels, components, nowcasts). This gives the agent clear decision guidance.

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