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

Annotations already declare read-only, idempotent, closed-world, so the description correctly spends its words elsewhere: nearest-first ordering, distances returned in meters, Korean-only naming, and geographic restriction to Korea (consistent with openWorldHint=false). It stops short of noting any rate limits, coverage caveats, or that a category filter can sharply reduce results.

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?

A single dense sentence that front-loads the operation and packs scope, ordering, unit and locale into it. Slightly awkward phrasing ('radius of a latitude/longitude') but no filler.

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 covers the key return traits (ordering, distance unit, Korean-only names) and the region constraint, which is enough to call correctly. It omits what fields come back per place and whether category filtering changes ordering or coverage, which would round it out.

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% with units, defaults, ranges and an enum legend already documented per-parameter. The description only alludes to radius and adds nothing about lat/lng ordering, limit behavior, or default radius, so it neither helps nor compensates.

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+resource+scope: proximity search by lat/lng within a radius, restricted to Korea. This meaningfully separates it from search_places (keyword) and get_related_places, though the description never names those siblings, so differentiation is inferential rather than explicit.

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 statement of when to use this over search_places, get_related_places, or generate_itinerary, and no prerequisites. The only usable cue ('within a radius of a lat/lng') is implied by the name and schema rather than stated as guidance.

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