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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description goes beyond that by disclosing data provenance and vintage (fares in effect since 1 June 2023, checked September 2026) and by stating that the response includes the source and page URL, which tells the agent the result is a cited estimate rather than a live quoted fare.

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?

It is short and front-loads the purpose, then the source and vintage. Minor waste in the awkward fragment 'Same code as <url>.' and the doubled label 'Reference: Source:', which could be trimmed without losing 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?

With no output schema, the description usefully covers the return shape (estimate plus source and page URL) and the data vintage, which is important for a regulated fare table. What is missing is any explanation of the four inputs, so the definition is only partially complete for a parameterized calculator.

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% across all four parameters, and the description compensates with nothing: it never explains that km is distance, hour drives a late-night surcharge, slow_traffic_minutes affects the time-based meter, or what outside_busan changes. Only the parameter names themselves and the schema's ranges/defaults carry any meaning.

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 states a specific resource and scope: a Busan regular mid-size taxi meter fare estimate, and it names the exact source (Busan Metropolitan City, fares effective 1 June 2023). It does not, however, distinguish itself from the sibling seoul_taxi beyond the city name, so an agent must infer the split from the tool name alone.

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?

Usage is only implied: the 'regular mid-size taxi' qualifier scopes it away from other taxi classes, and the URL points to the authoritative calculator. There is no explicit when-to-use statement, no mention of seoul_taxi or other fare tools as alternatives, and no note on prerequisites.

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