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

The description adds a real behavioral trait beyond the annotations: the cost of '$0.005 USDC per call,' which explains why readOnlyHint is false for an otherwise read-like operation and warns the agent about a monetary side effect. It stops short of noting rate limits or what triggers failure.

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 core function and appends the cost. Zero filler, every clause earns its place.

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 ideally covers returns, but for a simple two-param utility it is nearly complete: purpose, both modes, and pricing are present. The return format and error behavior are the only gaps.

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 0%, so the description must carry the load. It conveys the two modes (place name input vs coordinate input) which maps to the query/reverse params, but never explicitly ties the 'reverse' flag to its effect, leaving some inference to the agent.

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 and covers both directions: 'Geocode place names to lat/lon; reverse geocode coordinates to addresses.' An agent immediately knows what the tool does, and no sibling tool overlaps this capability.

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?

It implicitly signals the two modes (forward vs reverse geocoding via the coordinate/place-name distinction), but offers no explicit when-to-use context, prerequisites, or alternatives. Usage is inferable but not spelled out.

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