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

Annotations already provide readOnlyHint, destructiveHint, idempotentHint, and openWorldHint. The description adds value by specifying the data is 'chain-linked volumes, % change vs previous year', the dataset identifier 'tec00115', and the licensing 'CC BY 4.0'. It also clarifies the tool returns data for one country per call, which is a behavioral constraint beyond annotations.

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?

The description is a single, well-structured sentence that front-loads the core purpose and includes essential details (metric, source, license). No unnecessary words; every part is informative.

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?

The tool has an output schema (context signals), so return values are handled elsewhere. The description covers purpose, scope, and data source adequately for a simple read-only tool. Minor gap: no mention of authentication or rate limits, but annotations suggest these are not critical here.

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%, so the schema already describes parameters sufficiently. The description does not add extra meaning beyond the schema; it only restates the overall metric. With high coverage, a baseline of 3 is appropriate.

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 clearly states the tool provides 'Annual real GDP growth rate' for one EU country, specifying the metric, source dataset, and scope. This distinguishes it from sibling tools like finance.eurostat.inflation and finance.eurostat.population by naming the exact economic indicator.

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 implies usage for GDP growth data but does not explicitly guide when to choose this tool over siblings, nor does it state when not to use it. No alternatives or exclusions are mentioned, leaving the agent to rely on the tool name and context.

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