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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the description need not restate that. It adds domain context by enumerating the indicators available for retrieval, but says nothing about series frequency (daily/monthly/quarterly), how much history is returned by default, or what happens when no filter is supplied.

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 the core purpose front-loaded before the enumerated values. The long code list is necessary content rather than filler, though it slightly dominates the description at the expense of guidance.

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 not owed. However, all four parameters are optional and the description never states the default behavior when no code, category, or date range is provided, nor the series frequency — a real gap for a time-series tool.

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% and the four parameters are documented, which sets a baseline of 3. The description goes beyond the schema by listing the complete set of valid codes and categories, whereas the schema only offers examples ('e.g. "RBNZ_OCR"') and defines no enums. That materially improves correct invocation.

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 first sentence states a specific verb and resource: 'Get historical time series for a macro indicator.' An agent can distinguish this retrieval tool from siblings such as get_macro_regime or get_macro_exposure. It stops short of naming those siblings explicitly, so no direct differentiation is given.

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 supplies the valid values but never says when to reach for this tool versus alternatives (e.g. get_macro_regime for regime state, get_macro_exposure for portfolio exposure). The phrase 'Or filter by category' hints that code and category are alternative selectors but does not state precedence or whether they can be combined.

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