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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive), but the description adds value beyond them by disclosing that address text is sent to third-party geocoding services and that output is structured fields rather than an official postal confirmation. It stops short of rate-limit, auth, or error behavior.

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 action and its backing services are front-loaded, followed by the data-flow and caveat sentences. It is dense but each sentence earns its place; the trailing Korean one-liner is mildly redundant for an English-reading agent but serves localization.

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 3-parameter, no-output-schema tool with rich annotations, the description covers purpose, data handling, and the authoritative-use caveat. Return-field detail is not required since no output schema exists, and the described 'structured fields' hints at the shape.

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 100%, so from/to/address are already documented with patterns and examples. The description only implies language direction ('into another language') and adds nothing about code formats or the 200-char limit, so it sits at the baseline where the schema does the heavy lifting.

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?

States a specific verb (translate/transliterate) and resource (street address), and names the backing engines (WIA Address, OpenStreetMap Nominatim, Korean road-name API). It is clear what the tool does, but it never contrasts itself with the sibling address_korea_lookup, so an agent must infer the distinction.

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?

Gives a clear when-not: 'Do not use for mail delivery decisions without verifying with the local postal service,' and frames the operation as display translation rather than authoritative lookup. It does not name an alternative tool or state when to prefer address_korea_lookup, so routing guidance is incomplete.

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