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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: the result is a link handed to the person to 'fill in themselves', i.e. a human-in-the-loop handoff rather than a completed booking. It doesn't cover link lifetime, auth requirements, or whether the preset is persisted, which keeps it below a 5.

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 sentences, no filler, and the sibling routing advice comes after the core statement. The lead sentence is awkwardly constructed, which slightly hurts front-loading, but nothing is wasted.

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 one-parameter, no-output-schema link generator with read-only annotations, the description covers what it produces (a preset planner link), who uses it (the person themselves), and when to prefer the sibling. Missing only edge details like link expiry or whether the trip type can be changed afterwards.

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 0%, so the description carries the burden, and it only says the preset is tied to 'a trip type' without explaining the option set. In practice the enum values (beach_pool, bachelorette, wine_food, ski_snow, etc.) are self-descriptive, which prevents a lower score, but the description adds no meaning beyond the parameter name.

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 makes clear that the tool returns a link to a decidewhere.to trip planner page pre-set to a trip type, for the user to complete themselves, and it explicitly contrasts this with the sibling create_group_trip. The phrasing ('Link to decidewhere.to's trip planner preset to a trip type') is grammatically clumsy and never uses a clean verb like 'return' or 'generate', so the agent has to infer the exact output, but the resource and scope are distinguishable from siblings.

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?

It names the alternative (create_group_trip) and the exact condition that selects it: 'when you know where people are flying from'. The positive condition for this tool (use it when you don't know origins / want the person to fill it in themselves) is only implied, but the routing decision is clear enough.

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