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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds meaningful context beyond that: drive times reflect typical weekday rush-hour traffic, and auth requirements differ by caller type with a filters:read scope — both useful behavioral disclosures not in structured fields.

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?

Four compact sentences, front-loaded with the core purpose before the caller-type and indexing details. Each sentence carries distinct information; slight density but no waste.

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 should indicate what is returned (e.g., duration in traffic, distance, route info) but only says 'routed driving commute.' For a calculation tool where the return shape matters to an agent, this leaves a clear gap despite otherwise strong coverage.

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 67% with nested origin object. The description reinforces that origin is required for anonymous callers and explains location_index ties to search results, adding practical semantics beyond the schema. It doesn't clarify origin handling for connected callers (optional?), a minor gap.

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 specific verb (get) and resource (routed driving commute) scoped to a job site, with no ambiguity about what the tool produces. No sibling tool overlaps this function, so an agent can identify it immediately.

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?

Clearly distinguishes anonymous callers (origin required as {lat,lng}) from connected callers (saved origin, filters:read scope), which is explicit conditional guidance. It doesn't explicitly exclude use cases or name alternatives, but the caller-type split provides strong routing context.

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