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

Annotations already establish this as a read-only, idempotent, closed-world operation, so the bar is lower; the description still adds genuine value by disclosing return characteristics: history is ordered oldest-first, and min/max are computed over the requested window. It does not state error behavior for an unknown key, but overall it meaningfully supplements the annotation set rather than restating it.

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 tight sentences with zero filler; the payload contents are front-loaded and the usage cues come last. The phrasing is dense to the point of being telegraphic ('freshness', 'next release' without elaboration), but every clause earns its place.

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?

An output schema exists, so return shape need not be explained, and both parameters are fully documented in the schema. Safety profile is covered by annotations. What remains unaddressed is failure behavior for an invalid or unknown indicator key, a realistic concern given the strict key pattern — a minor but real gap for an otherwise complete definition.

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 description coverage is 100%, and the schema already explains that 'key' comes from list_macro_indicators and that 'from' is a YYYY-MM first month defaulting to five years. The description's only addition is the notion of a 'window' tied to min/max, which is a marginal clarification rather than new semantics. 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?

Names a specific retrieval target (a single indicator identified by key) and enumerates exactly what comes back: meaning, latest reading, freshness, next release, and history with min/max. The phrase 'one indicator by key' implicitly separates it from compare_macro_indicators (multi-indicator) and list_macro_indicators (enumeration), but that differentiation is only implied rather than stated.

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?

The final sentence gives concrete question shapes ('what is the current X', 'how has X changed') that map cleanly onto the tool, which is stronger than most definitions offer. However, no sibling is named as an alternative and there are no exclusions — nothing tells the agent when to prefer get_macro_snapshot or get_macro_changes instead.

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