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

Annotations already provide readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds the exact count of 462 entries, the data source (api.uis.unesco.org), no auth required, and the CC BY-SA 4.0 license, which are useful behavioral and licensing details beyond the structured annotations. No contradictions.

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?

Three concise sentences, front-loaded with the primary action and scope, followed by usage guidance, an example, and data provenance. No redundancy or fluff; every sentence earns its place.

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 low complexity, the presence of an output schema, and annotations covering safety, the description is complete. It covers what the tool does, how to use it, an example, and the data source. An agent can confidently invoke it correctly without missing information.

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 schema already covers both parameters with descriptive text (query as case-insensitive substring, type as enum). The description adds a concrete example ('query='Kenya'') and ties the purpose to finding codes for get_data, which provides context beyond the schema. With 100% coverage, this adds meaningful value.

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 verb 'List' and the resource: the 462 country and world-region codes recognized by the UNESCO UIS API. It specifies that the tool is for finding valid geo_unit codes for use with unesco-data.get_data, which distinguishes it from sibling tools like indicator_search and get_data.

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 explicitly says 'Use this to find a valid geo_unit code for unesco-data.get_data', giving a clear use case. It also mentions optional filters for name or level. It does not explicitly list alternatives or when not to use, but the purpose is unambiguous and the usage context is clear.

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