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

The description adds behavioral context beyond the annotations: it is static and versioned, takes no inputs, and should be called once per session. The annotations already cover read-only and idempotent behavior, so the description's snapshot semantics and call cadence are valuable additions without redundancy.

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 sentences with the core purpose front-loaded and the usage directive stated crisply. There is no wasted wording, and no information is repeated from the annotations.

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?

For a zero-input reference tool, the description is complete: it defines what the response covers, the call cadence, and the no-input contract. Since there is no output schema, describing the response contents in prose was necessary and sufficient.

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 has zero parameters and an empty input schema. The description explicitly states 'No inputs,' which removes any ambiguity and earns the baseline credit for a zero-parameter tool.

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?

The description states this is a static, versioned dictionary of every field the surface emits, including units, value sets, meanings, and shared response conventions. This clearly identifies the resource and purpose, and distinguishes it from data-query siblings like get_day or get_regime by being a metadata reference tool.

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 description gives clear usage context: it is a no-input reference to call once per session, so an agent knows when to invoke it and that the result can be reused. It does not explicitly name alternatives or state when not to use it, but the distinction from the data-query siblings is clearly implied.

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