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

Annotations already declare readOnly, idempotent, closed-world, non-destructive, so the safety bar is met structurally. The description still adds real behavioral value by promising no address transfer and no account creation, which is the key concern for a link-handoff tool. It stops short of describing the returned link's form or any environment prerequisites.

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?

Three short sentences, front-loaded with what the tool does, then the eligibility rule, then the side-effect disclaimer. No filler and nothing repeated from the schema or annotations.

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?

For a single-enum, no-output-schema tool with strong annotations, the definition covers purpose, gating conditions, and side effects sufficiently to invoke it correctly. The only soft spot is that no output schema exists and the description only loosely characterizes the return value as 'a link'.

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 0%, so the description must carry the meaning, and it does: the prose triggers map cleanly onto the three enum values (multiple_drivers, time_windows, stop_limit), including the 20-stop threshold that the enum name alone does not convey. It does not state that exactly one reason must be chosen or how to disambiguate when several apply.

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 gives a concrete verb and resource: it shows a link to Spoke Dispatch, a route planner, and scopes it to needs the free planner cannot cover. The closing sentence ('it does not transfer addresses or create a Dispatch account') implicitly separates it from create_route/create account flows, though it never names a sibling 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?

It states exactly when to use it ('only when the user explicitly asks for one of those') and enumerates the three qualifying conditions: multiple drivers, enforced delivery time windows, or more than 20 stops. The exclusion ('only when... explicitly asks') is an explicit when-not clause that prevents over-triggering.

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