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

Annotations already declare readOnlyHint=true, and the description aligns, adding behavioral details like checking dead legs and warning about poison carriers, plus estimating bookability. This enriches context beyond the read-only flag without contradiction.

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 two sentences, front-loaded with purpose, and every sentence adds value. It is concise and clear with no filler.

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 read-only validation tool with no output schema, the description adequately covers what it does, when to use it, and the checks performed. It hints at output via 'estimates bookability' but could be slightly more explicit about the result format, though not critical.

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?

The input schema covers all three parameters with 100% description coverage. The tool description does not add extra semantics beyond the schema, so it meets the baseline but no more.

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 clearly states the tool validates a multi-city flight routing for feasibility, using the specific verb 'validate' and resource. It enumerates specific checks (alliance carrier rules, dead legs, poison carriers, bookability) that distinguish it from sibling routing and planning tools.

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?

Provides explicit when-to-use guidance: 'Use this before building an itinerary to catch routing problems early.' It does not mention alternatives or when not to use, but the context is sufficient given sibling tools like plan_route and route_suggest.

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