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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds no behavioral context beyond that — no auth requirements, rate limits, or caching/staleness notes; its enumeration of fields is payload content rather than behavior. The vague 'payment boundary' phrase hints at a constraint but is never explained.

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?

It is a single sentence with the verb front-loaded, which is good, but nine comma-separated output fields read as a payload dump that largely duplicates the output schema. The sentence is efficient in syntax yet spends most of its words on redundant content rather than usage or parameter meaning.

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?

Because an output schema exists, the return-value enumeration is not strictly necessary, and annotations carry the safety profile, so the description's minimum obligations are purpose plus call conditions. It covers purpose but leaves the market/route_code parameter semantics and the relationship to the preview_* siblings undocumented.

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 only 50%: the two agent_* compatibility fields are documented in the schema, while 'market' (enum) and 'route_code' (pattern/length) have no descriptions. The description says 'one route's' without explaining route_code semantics, and never mentions the market parameter at all, so it fails to compensate for the uncovered half.

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 ('one route's' details) and enumerates the payload: provider, directions, prices, vehicle classes, required fields, quote template, landing page, booking URL, payment boundary. An agent can tell this is a single-route detail lookup versus the plural list_destinations sibling. It never names the preview_* siblings it could be confused with, so the distinction relies on the reader inferring 'details' vs 'quote'.

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?

There is no when-to-use, when-not-to-use, or prerequisite guidance. With siblings like preview_transfer_quote and preview_private_driver_quote available, the agent gets no signal about why it would fetch details instead of previewing a quote, or in what order (list_markets → list_destinations → get_destination_details).

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