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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely useful behavior the annotations don't: return times are today-only, prices span the next 30 park-local days, and the tool cannot transact. It stops short of describing response shape or how many rides are returned.

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 tight sentences, front-loaded with the use trigger, followed by temporal constraints and the capability boundary. Every sentence carries information; there is no filler or restatement of the title.

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 carries the burden of describing returns, and it does explain what the two data modes yield (prices vs. return windows) plus their date limits. It is slightly thin on the response shape (e.g., per-ride list structure, whether prices vary by ride), which keeps it from a 5.

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 park_id, date, and ride_id are all already documented in the schema with their defaults and formats. The description's temporal notes ('return times only for today') overlap with the date parameter's own description rather than adding new parameter-level meaning. 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?

The description names a specific resource (Lightning Lane / Universal Express prices and return times) with clear scope, and it implicitly distinguishes itself from sibling parky_get_ticket_prices by scoping to Lightning Lane rather than admission. An agent can tell exactly what data this returns without opening the schema.

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 states the triggering user question ('when a visitor asks what Lightning Lane costs... or which rides have return times available now'), the temporal validity of each data type, and an explicit negative boundary ('Parky cannot buy or book Lightning Lane'). Nothing about when to reach for this tool is left to inference.

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