list_zones

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

No annotations are provided, so the description carries the burden. It discloses that the tool lists zones and that it can filter by parent or name, but it doesn't mention any side effects, performance implications, or limitations (e.g., pagination, rate limits). For a read-only listing tool, this is acceptable but not rich.

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 concise, with a clear first sentence and a helpful example. It front-loads the core purpose and then provides a usage example. The only minor issue is that the 'contains' parameter is not mentioned, but the overall structure is efficient.

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 that there is an output schema (not shown but indicated), the description doesn't need to explain return values. However, it doesn't clarify the exact format of the 'level' values (e.g., are they strings like 'NUTS2'?) or the 'contains' parameter semantics. For a tool with 3 parameters and a clear workflow, it's adequate but could be more complete.

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 0%, so the description must compensate. It explains the 'level' parameter (NUTS0-3 or CITY) and the 'parent' parameter via the example, but it doesn't explain the 'contains' parameter at all. The description adds some meaning beyond the schema (which only has titles and defaults), but it's incomplete for one of the three parameters.

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 lists zones for a given NUTS level or CITY, with optional parent or name filtering. It distinguishes itself from siblings like get_indicators and search_indicators by specifying its role in the workflow (feeding codes into get_indicators). However, it doesn't explicitly contrast with list_codes, which might be a similar listing 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 a concrete example (list_zones("NUTS2", parent="FR")) and states that the output codes feed into get_indicators, giving clear context for when to use this tool. It doesn't explicitly mention when not to use it or alternatives, but the example and workflow hint are strong guidance.

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