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

Annotations only declare readOnlyHint and openWorldHint; the description adds genuinely new behavior — short-link expansion, headless-browser fallback for obscured stop names, and an explicit latency warning of up to a minute. That latency disclosure is exactly the kind of context an agent needs to plan a call.

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 sentences, front-loaded with what is returned and followed by the operational caveats. No filler and nothing repeated from the schema.

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?

Output shape is described (stops with names/coordinates, plus region) and there is no output schema to defer to, so this is close to complete. It doesn't cover failure behavior for malformed or non-directions links, which would matter for an open-world tool.

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 baseline would be 3, but the description amplifies the useBrowser parameter by tying browser mode to its cost (slow, up to a minute). The url parameter's accepted forms are already fully documented in the schema.

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 precise verb and resource: extracts stops (names + coordinates) and the likely region from a Google Maps directions link. The resource (a shareable URL) is distinct enough from geocode/get_route that an agent can select it, but the description never names or contrasts those siblings explicitly.

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?

Gives clear context for when the tool applies (a Google Maps directions link, short or full) and explains how hidden-name links are handled, including that browser mode is slow. It stops short of stating when to prefer get_route or geocode over parsing a link.

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