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

Annotations already cover read-only/idempotent/non-destructive safety, and the description adds substantive behavior beyond them: UTC time basis, that tracked releases return previous and then new readings and never a forecast, that policy-rate figures are omitted, that forward visibility is capped, and that each call consumes one quota unit while a rejected argument costs nothing.

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-loads purpose first, then routing, then parameters, then behavior, so an agent can stop reading at any point. The behavioral and parameter sentences are densely clause-stacked, which costs some readability, but almost every clause carries operational information.

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-value explanation is rightly omitted. With routing, defaults, limits, quota behavior, and UTC semantics all present, an agent has everything needed to call this correctly and interpret the results.

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 already documents defaults and the 400-day limit, so the baseline is 3. The description adds genuine value over the schema: concrete UTC timestamp syntax, the Sunday-to-Sunday week pattern, the effective default window (one day ago to 31 days ahead), and the single-domain filter semantics.

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 ('List scheduled decisions and releases in a time range, in time order') and enumerates the event categories covered (central-bank decisions, earnings, votes, speeches, etc.). It explicitly distinguishes itself from list_changes and search_changes for past/reported events, so an agent can route without opening the schema.

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 when-to-use ('what is coming or has just passed') and when-not ('what has already happened and been reported') with the named alternatives list_changes and search_changes. It even supplies the concrete recipe for a common case ('for one week ask from a Sunday 00:00Z to the next Sunday').

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