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

Annotations already declare readOnly/openWorld/non-destructive, so the description is free to add the non-obvious part — tier-based response gating: composite+regime+2 categories unauthenticated, 4 signed-in, all six with Pro. That is exactly the kind of auth/entitlement behavior an agent cannot get from the schema, and it materially affects how results should be interpreted or explained to a user.

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 dense sentences: the return payload and its components come first, then entitlement gating, then trigger phrases. Every clause carries information; nothing is boilerplate.

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?

No output schema exists, so the description bears full responsibility for describing return values — and it does, enumerating the composite, regime, and category scores plus which tiers receive how many. Combined with the entitlement disclosure, an agent has everything needed to call and interpret the result.

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% and the single `topic` parameter is fully described there, including the enum. The description only reinforces that macro is "the only topic", adding no syntax, format, or default behavior beyond the schema — baseline 3 for a high-coverage schema.

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?

States precisely what is returned: a 0–100 US macro-health composite, a regime call, and six named category scores (growth, labor, inflation, rates, liquidity, sentiment). The resource is unambiguous, but the description never contrasts itself with siblings (best_price, fed_rate_odds, race_odds, senate_map), relying on domain obviousness for 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?

Provides three concrete trigger phrasings ("how is the US economy", "macro regime", "risk-on or risk-off") that map directly onto the tool, which is clear usage context. It stops short of explicit exclusions or naming alternative tools, so it lands at 4 rather than 5.

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