Compare an indicator's value across its official sources

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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive, and the description adds substantial behavioral context: independent fetching per source, per-value citations, spread calculation, methodological rather than error-based differences, and resilient handling of down sources. This goes well beyond the structured 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?

Every sentence earns its place: function, concrete examples, use cases, interpretation caveat, expected output, and failure behavior. The most important action and scope are front-loaded, and the description is dense without being bloated.

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 read-only comparison tool with no output schema, the description covers what the result contains (values, citations, spread, definitions), how to interpret differences, and what happens when sources fail. An agent has enough context to select and invoke the tool correctly.

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 documents indicator, country, and period. The description reinforces the single-indicator/single-country scope and gives indicator examples, but does not add meaningfully beyond what the input schema already provides. Baseline 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?

States a specific verb ('Fetch...from EVERY official source...independently') and resource ('one indicator for one country'), with concrete examples and the side-by-side plus spread output. Clearly distinguishable from siblings like get_indicator or get_series, which retrieve single series rather than cross-source comparisons.

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?

Explicitly says when to use: when sources disagree, when you need to know which official number to cite, or to assess methodological gaps. It gives clear context but does not name alternative sibling tools or state when not to use it, so it stops just 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.