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

The description presents a read-only search operation ('Searches cash fares', 'combines the best cash leg...'), yet the annotations set both readOnlyHint=true and destructiveHint=true. This is a direct contradiction with the described search-only semantics, and the description does nothing to clarify potential side effects, charges, or destructive behavior.

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?

The description is compact and front-loaded: the first sentence states the core purpose, followed by supporting detail, target use case, and the paid-feature warning. Every sentence earns its place, though the second sentence slightly restates the first.

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?

This is a complex hybrid search with no output schema and conflicting destructive/read-only annotations. The description explains the algorithm well, but it does not clarify return format, invocation side effects, or how the paid feature is charged, leaving significant ambiguity for an agent deciding whether to call it.

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 40%; only cabin and points_value_cents have descriptions. The description adds useful algorithmic context for how these parameters matter ('cash leg with the best award leg', 'premium cabins'), but it does not explain non-schema-covered parameters beyond what their names and patterns imply. It partially compensates for the low coverage but leaves some meaning implicit.

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 names a specific verb and resource: 'Find the cheapest way to fly by combining cash tickets with award redemptions into one split-ticket journey.' It also specifies data sources (Google Flights, award availability) and the target use case (premium cabins, long-haul), which clearly separates it from siblings like search_cash_flights and search_availability.

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?

The description gives clear context for when to use it: 'Best for premium cabins (business/first) on long-haul routes' and warns that it is a 'Paid feature.' It does not explicitly state when not to use it or name alternative tools, so it stops short of full when/when-not guidance.

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