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

Beyond the readOnly/openWorld annotations, the description discloses the match limit (5), the returned fields (display name, lat/lon, country code, type), 7-day caching, attribution/licensing (OpenStreetMap, ODbL), and a precise payment model: $0.002 USDC per successful call via x402 on Base/Solana/Arc with failed calls uncharged. These are exactly the behavioral traits an agent needs before invoking a paid, cached geocoder.

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 capability is front-loaded in the first two sentences, followed by attribution and pricing details. It is dense but every sentence carries operational information (match cap, returned fields, license, caching, pricing); nothing reads as 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?

Given a paid external geocoding tool with an output schema present, the description covers the critical unknowns: cost, payment rail, billing on success only, caching duration, attribution requirements, and the shape of results. An agent can decide whether to call it and how to interpret the two modes without further documentation.

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 the baseline is 3. The description adds value by clarifying the two mutually exclusive modes — a name query returning up to 5 matches versus a coordinate pair returning the place at that location — which reinforces how q versus lat/lon are intended to be used together.

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 states a specific verb+resource pair ('Place names to coordinates and back') and covers both forward and reverse geocoding in one sentence. It is clear what the tool does, but it never names or distinguishes itself from nearby siblings such as us_geocode, places, or address_parse.

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?

Usage is implied by the two modes described ('up to 5 matches for a name, or the place at a coordinate'), so an agent can infer when each branch applies. However, there is no explicit guidance on when to prefer this over us_geocode, places, or address_parse, and no stated prerequisites or exclusions.

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