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

The annotations already declare readOnlyHint=true and openWorldHint=true. The description adds significant behavioral detail beyond those: free tier access without a key, that composite/regime are always free, 2 category scores are free, one email returns 4, and Pro returns all six. This gives the agent important expectations about response content and access limitations. It does not contradict the annotations, but the description does not fully explain the 'open world' nature (e.g., live data variability), hence not a 5.

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 compact and front-loaded: it lists the outputs, then the usage/pricing tiers, then clear use cases and an exclusion. Every sentence adds distinct value with no fluff or repetition of schema details. The structure is logical and efficient.

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?

With no output schema, the description adequately explains the main return elements (composite, regime, six category scores) and the tier-dependent availability. It also clarifies the single parameter and sibling exclusion. Minor ambiguity remains around 'one email returns 4' (which may confuse) and whether category scores share the 0–100 scale, so it is not a perfect 5, but it is sufficient for correct selection and invocation.

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 input schema has 100% description coverage: the only parameter 'topic' has an enum, a default, and a clear description ('macro = US macro-health composite (the only topic — NFL is now the nfl_edge tool)'). The tool description does not add any semantic meaning beyond what the schema already states, so baseline 3 applies.

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 that the tool returns the US macro-health composite (0–100), regime, and six category scores, with explicit examples of user intents ('how is the US economy', 'macro regime', 'risk-on or risk-off'). It also distinguishes itself from siblings by noting NFL edges moved to the dedicated nfl_edge tool, providing both a clear scope and differentiation.

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 provides explicit use cases ('Use for...') and an explicit exclusion/alternative: 'NFL edges moved to the dedicated nfl_edge tool.' This tells the agent exactly when to choose this tool and when to use the sibling instead, which is strong usage guidance.

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