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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered; the description adds genuinely useful context beyond that: the required permission scope, the GET endpoint path, and the capacity formula for maxAllowedStops. It does not say what happens on a permission failure, but for a trivial read this is solid.

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?

Two short, front-loaded sentences with zero filler: the returned fields come first, then the auth requirement and endpoint. Every clause carries information an agent can act on.

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 must carry the return value, and it does by naming the three limit fields explicitly. It stops short of stating value types/units or the failure mode when the permission check fails, which keeps it just below complete.

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 tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description instead spends its words on the returned fields, which is the right choice here.

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?

Names the exact resource (itinerary planning limits) and enumerates the three values returned, including the derived semantics of maxAllowedStops (shipments x 2). This is clearly distinguishable from the sibling plan/save/optimize tools, which mutate plans rather than read settings.

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?

States a hard prerequisite (an Operations App user with ITINERARY_PLANNING_ACCESS) but never says when to call this versus the sibling planning tools, nor what to do when the permission is missing. Usage is implied by the read-only settings nature of the endpoint rather than explained.

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