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 non-structured context: the $0.0025 USDC x402 per-call cost and which upstream provider handles which query type. It omits rate limits and multi-result/pagination 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?

Two tight sentences: the core transformation and returned fields come first, then source attribution, then the cost note. Nothing is redundant and the most decision-relevant information is front-loaded.

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 carries the return-value burden and does so by enumerating returned fields. Combined with cost and data-source disclosure this is nearly complete, though it does not explain what multiple results (limit up to 10) look like or their ordering.

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 coverage is 100%, so both parameters (q, limit) are already fully documented in the schema. The description adds no syntax, format, or interpretation details beyond the schema, 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?

Specific verb (geocode) plus the exact resource types (place, landmark, street address) and the output fields (lat/long, city, region, country, postcode, timezone, population). It is clearly distinguishable from geo siblings like places, route, or isochrone.

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?

The description explains the split data sources (GeoNames for cities, OpenStreetMap for addresses and POIs), which implies appropriate use cases. However, it never names an alternative sibling (e.g. places for POI search) or states when not to use it, 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.