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

Adds useful behavioral context beyond annotations: timezone (UTC), official data sources, event importance, and a cost indicator ($0.005). Annotations already cover read-only, idempotent, non-destructive safety, so this is solid additional context.

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, front-loaded with the core purpose and a concrete usage instruction. The event list is long but earns its place by making the tool's scope unambiguous.

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?

Given full schema coverage and strong annotations, the description is nearly complete for a low-complexity calendar tool. It could say more about return shape, but an output schema is absent and the event data is sufficiently characterized.

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%, so the schema already documents all three parameters including enums. The description reinforces importance and timezone but does not add much parameter-specific meaning beyond what the schema provides.

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?

Clearly states the resource (market-moving macro events) and scope (next events, UTC, with importance, from official calendars), with concrete event examples. It is distinguishable from siblings like macro.fed_odds, though it does not explicitly name an alternative.

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 a clear usage context: 'Check before opening a position.' It does not state when not to use it or name an alternative sibling, but the intended timing is explicit.

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