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

With no annotations, the description carries the full burden and does so well: it discloses tier gating (free level is one day behind; Pro keys of EM FX News & Sentiment unlock the score, 90-day norm, article count, early signal, topics, and predictive links), plus a confidence qualifier on the correlation figures. Missing only error/empty-data behavior and freshness beyond 'one day behind'.

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?

Front-loaded with the core purpose, then cleanly split into no-currency and with-currency branches. The Pro-feature enumeration is long but each item is a genuinely distinct output field, so little is wasted; a slight trim of the trailing list would tighten it.

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?

Although an output schema exists and return values need not be explained, the description still surfaces the Pro/free split that the schema cannot express, which is critical for correct invocation. Gaps are minor: no guidance on invalid currency codes, coverage boundaries, or what happens when a currency has no recent articles.

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%, so baseline is 3; the description adds value by explaining what the `currency`-absent branch actually returns (a ranked map of the 7-day fall in tone) rather than just restating 'omit for the map'. The `lang` parameter is left entirely to the schema, which is acceptable given its full description there.

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+resource (what the news says about a currency's country, day by day) and immediately distinguishes two distinct outputs: the ranked coverage map without a currency, and the per-currency daily reading with it. No sibling tool overlaps this, so an agent can select it from the name plus first sentence alone.

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?

Explicitly tells the agent when to omit `currency` (get the map) versus supply it (get the latest day), which is the primary routing decision for this tool. It does not, however, contrast itself with adjacent siblings like get_stress_signals or get_official_vs_street, nor state prerequisites for Pro-only fields.

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