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

Annotations already cover read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower; the description still adds meaningful context the annotations cannot: exactly 22 series, coverage beginning 1960, missing years preserved rather than interpolated, and staleness ('Not real-time'). That is real behavioral disclosure beyond structured fields.

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 compact sentences with the verb and scope front-loaded and no filler. The middle clause ('units, definitions via records') is slightly compressed and reads awkwardly, costing a point against perfect clarity.

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?

With an output schema present, return-value shape need not be explained, and the description covers data scope, temporal coverage, gap handling, and freshness. The only gap is the lack of routing guidance relative to get_historical_indicators.

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?

The tool takes zero parameters, so per the baseline there is nothing for the description to document and no risk of under-specification. Nothing in the text misleads about inputs.

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?

It pairs a specific verb ('List') with a specific resource ('twenty-two annual World Bank historical series') and enumerates what the listing contains (units, definitions, collection status). It stops short of explicitly distinguishing itself from the sibling get_historical_indicators, which is the main ambiguity an agent faces here.

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?

'Not real-time' and 'coverage starts in 1960' imply when this catalog-style tool is appropriate versus a live-data retrieval, but no alternative tool is named and there is no explicit when/when-not guidance. Usage is left to inference.

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