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

The description discloses return value structure (value per country, approximate EUR conversion, source, validity date) and the fallback to a list of available topics when no match. Since no annotations are provided, the description adequately covers behavioral traits like being read-only, though it could mention any potential side effects (none expected).

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, comprising two sentences that efficiently convey purpose, usage, input format, and output details. No redundant information.

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?

The description is complete for a simple comparison tool given no output schema. It explains the return format and fallback behavior. It could mention error handling for invalid inputs beyond no match, but overall sufficient.

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 covers 100% of parameters, but the description adds valuable context: it provides example values ('minimalna mzda', 'vat') and explains the optional topic parameter as a precise identifier. This enhances understanding beyond the schema's basic descriptions.

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 compares one metric across all available countries, provides concrete examples (minimálna mzda, DPH, daň z príjmu firiem), and describes the output format. This distinguishes it from sibling tools like lookup_fact (single fact) and list_facts (listing).

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 gives guidance on when to use the tool (to compare a metric across countries) and how to specify input (query or topic). It also explains the fallback behavior when no match is found. However, it does not explicitly mention when not to use it or point to alternatives among siblings.

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