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

Annotations already declare readOnlyHint and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context: it returns an estimate along with source and page URL, and it pins the fare vintage (effective Feb 2023, checked Sept 2026). It does not explain what the estimate includes (tolls, surcharges) or how late-night rates are applied.

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 core purpose is front-loaded, but 'Same code as <calculator URL>' is developer-facing metadata with little value to an agent, and the 'Reference: Source:' wording is redundant. The vintage sentence earns its place; the URL sentence largely does not.

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?

For a read-only calculator with no output schema and no nested objects, the description covers the essentials of what comes back. However, with half the parameters undocumented and no explanation of the estimate's components, an agent cannot fully reason about the result's scope.

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 only 50%; only hour and slow_traffic_minutes are documented in the schema. The required km and the outside_seoul flag have no description anywhere, and the description adds no parameter meaning beyond naming the inputs indirectly.

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 names a specific resource and scope: a Seoul regular mid-size taxi fare meter estimate, and differentiates the city implicitly via the name (vs the busan_taxi sibling). It is clear what it computes, though it does not explicitly contrast itself with busan_taxi in prose.

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?

No when-to-use or when-not-to-use guidance is given. There is no mention of when to prefer this over busan_taxi or a generic travel_budget tool, and no prerequisites such as flagging that the fare table has a fixed vintage.

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