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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent mutation. The description adds genuine behavioral context beyond that: the ordering dependency on create_trip and the downstream constraint that destinations/options cannot exist without a variant. It omits the practical consequence of non-idempotency (calling twice creates two variants).

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 front-loaded sentences: purpose with examples first, then the prerequisite/sequencing, then the key dates constraint. Every sentence carries information and there is 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 create tool with annotations and a rich nested schema, the description covers purpose, prerequisite, and the dates model. It does not state what the call returns (e.g. the new variant id needed for subsequent add_destination calls) and there is no output schema to fall back on, leaving a minor gap.

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 100%, so the schema already documents tripId, name, dates (both shapes), participants, and notes. The description only restates the dates duality ("exact start/end dates or a flexible window with min/max nights") that the schema already explains, adding no new syntax or format detail. Baseline 3 applies.

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+resource ("Add an alternative version of the trip") with concrete examples ("Beach option" vs "Mountain option") that make the concept unambiguous. It is clearly distinguishable from siblings like duplicate_variant, update_variant, and select_variant.

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?

Explicit sequencing guidance: "create one right after create_trip" and the prerequisite that a trip needs at least one variant before it can hold destinations or options. It does not, however, mention alternatives such as duplicate_variant for copying an existing variant.

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