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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior. The description adds meaningful context by specifying the data returned (publisher, counts, freshness), the set of 18 countries, and the recommended ordering. It does not introduce contradictions or omit significant behavioral details.

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, informative sentence that front-loads the purpose and provides a useful country list. While the list is long, it is directly relevant to the tool's scope. It is not overly verbose and every part contributes to understanding the tool.

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?

Given the tool's simplicity (no parameters, no output schema) and the presence of comprehensive annotations, the description is complete. It explains what data is returned, the geographic scope, and when to call the tool, leaving no critical gaps.

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 has zero parameters, so the schema and description do not need to explain parameter semantics. The baseline for no parameters is 4, and the description appropriately avoids over-explaining, making it easy to invoke.

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's function: it reports which open-contracting procurement data is available, including per-country publisher, counts, and freshness. It distinguishes itself from siblings by explicitly saying 'Call this first' to learn data availability before relying on it, making it a unique precursor tool.

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 provides explicit when-to-use guidance: 'Call this first to learn... before relying on it.' It implies the tool should be used before querying specific data, but does not name alternatives or when-not-to-use scenarios. This is clear context, though not fully exhaustive.

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