Top host / origin countries

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

Annotations already indicate read-only and open-world hints. The description adds value by explaining the default behavior ('by' defaults to 'asylum'), the effect of 'normalize_by' with a concrete example, and the dependency on the worldbank provider for normalization. This goes beyond what annotations provide, though it does not cover all potential behavioral nuances like rate limits.

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 extremely concise, consisting of two sentences. The first sentence states the primary purpose, and the second elaborates on key parameters with an example. Every word serves a purpose, with no redundancy or unnecessary detail.

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 complexity (5 parameters, output schema present), the description covers the essential behavioral aspects: metric ranking, two main parameter groups, normalization effect, and provider dependency. The output schema handles return values, so description is complete for an agent to use the tool effectively.

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 input schema has 100% coverage with descriptions. The tool's description enhances understanding by explaining the meaning and default of 'by', the impact of 'normalize_by' with a vivid example ('Lebanon and Chad ahead of large economies'), and the provider dependency. This provides meaningful context beyond the schema alone.

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 ranks countries by a displacement metric for a year, specifying verb and resource. It explains the 'by' and 'normalize_by' parameters with examples, making the purpose distinct. However, it does not explicitly differentiate from sibling tools like 'refugee_population' or 'trend_analysis', preventing a score of 5.

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 usage details for parameters (e.g., default 'by' value, effect of 'normalize_by') but offers no guidance on when to choose this tool over alternatives. No explicit context for when not to use it or which sibling tool might be better suited is given.

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