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

Annotations already declare readOnly/idempotent/no destructive behavior, but the description adds non-obvious operational context the annotations cannot carry: partial failures are surfaced under 'missing' rather than failing the call, a 60 calls/minute per-IP rate limit, no authentication, and an update cadence of at most once per business day.

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?

Long but front-loaded and dense: the indicator inventory comes first, then usage/routing, then behavioral caveats. Every clause earns its place — the indicator list determines scope, the sibling list determines routing, and the tail covers failure mode, limits and freshness.

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 an output schema present, return-value structure needn't be restated. The description still covers everything else an agent needs: scope, alternatives, partial-failure behavior, rate limit, auth and data freshness.

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 takes zero parameters, so the baseline is 4 and there is no parameter syntax for the description to clarify. It usefully explains what the call returns per indicator (value, date, source, page URL, change vs 7/30 days and one year), which substitutes for parameters in shaping expectations.

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 a specific verb and resource ('Return the current value of Argentina's headline indicators in one call') and enumerates exactly which indicators are covered, so an agent can tell whether a user question about the blue dollar, EMBI or reserves is in scope. It is clearly separable from siblings that cover history, projections or weekly narrative.

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?

Gives an explicit positive trigger ('how is the economy doing today', comparing now vs a week/month/year ago) and names three alternatives with their selecting conditions: get_series for history, get_projection for the future, get_weekly_summary for a closed week's narrative. Nothing is left to inference.

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