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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful behavior: batch cap of 10, the returned fields, the cache-vs-fresh-lookup distinction, and crucially that unfindable addresses are reported rather than guessed.

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?

Two tight sentences with no filler, and the output shape and batch limit are front-loaded. The parenthetical 'from cache or a fresh lookup' is slightly compressed but still readable.

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?

There is no output schema, so the description usefully compensates by naming the returned fields (lat, lng, confidence) and the failure behavior. What remains thin is routing guidance against siblings, but the core call contract is complete.

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?

With a single parameter and 100% schema coverage, the schema already documents 'addresses' as '1–10 addresses'. The description's 'up to 10 addresses' confirms the constraint but adds no syntax or format detail beyond it, so the baseline 3 applies.

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 name plus 'Coordinates for up to 10 addresses (lat, lng, ...)' makes the resource and output explicit, and the batch scope is stated. It implicitly contrasts with the reverse_geocode sibling via the name, but the description itself doesn't name or distinguish from any sibling.

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?

There is no when-to-use or when-not-to-use guidance, and the obvious sibling (reverse_geocode) is never referenced. 'from cache or a fresh lookup' hints at behavior but does not tell an agent when this tool is the right choice.

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