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

Goes well beyond the annotations: discloses that reads come from a committed snapshot so latency is immediate, that the snapshot date is embedded in the answer, and the full billing model ($0.01/call, 25 free, failed calls free, repeats not free). This also explains the idempotentHint=false annotation rather than contradicting it.

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 what the tool returns and the country identifier format, then covers provenance and pricing. Slightly heavy on payment mechanics for a tool description, but every sentence is informative and none are tautological.

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?

No output schema exists, so the description carries the return contract itself: both series, units as % of labour force, 1-10 years newest-first, and the snapshot date included in the answer. An agent can call this without further discovery.

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%, so the baseline is 3, but the description adds meaning the schema lacks: accepted ISO forms (SE, SWE) alongside English names, and that years are returned newest-first. It does not describe edge cases such as unknown country names or out-of-range years.

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 (unemployment rate, total plus youth 15-24, as % of labour force) plus the data source and coverage window. It is clearly distinguishable from siblings econ_gdp, econ_inflation and econ_population, which cover different indicators.

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 a clear usage context ("Use for labour-market and macro questions") and a concrete invocation example (country=SE). It does not explicitly name an alternative tool or state when not to use it, so it stops short of full routing guidance.

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