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

Annotations already establish read-only, idempotent, and non-destructive behavior. The description adds a concrete behavioral detail beyond annotations: the API key can be supplied via headers or a query parameter and selects Pro when valid, which affects authentication and result quality.

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 short sentences with no filler; the domain is stated first and the API key note is kept separate. It is efficient, though slightly fragmentary and could have used the space to add usage 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?

For a tool with an output schema and safety annotations, the description covers read-only behavior and an auth detail, but it omits when to use the tool, what the timeframe values mean, and how indicators map to specific enum choices. An agent would still need to inspect enums and infer behavior.

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 0%, so the description must compensate, but it only loosely maps to the indicator enum (CPI, PPI, expectations, breakevens) and says nothing about the timeframe parameter. It helps categorize indicators but does not define individual enum values or timeframe 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?

The description identifies the tool as covering inflation-related indicators such as CPI, PPI, expectations, and breakevens, which clearly distinguishes it from sibling forecast tools. It lacks an explicit verb like 'returns' or 'forecasts', but the tool name and title supply that context.

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?

No guidance is given about when to use this tool over forecast_rates, forecast_gdp, or other siblings. The only operational note is about the optional API key, which is not a usage-selection guideline.

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