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

Annotations already cover the safety profile (readOnly, non-destructive, not open-world), so the description focuses on what those annotations cannot convey: data windows ('return times exist only for today; prices cover the next 30 park-local days') and the no-purchase limitation. It does not describe response shape or whether a full ride list is returned when ride_id is omitted.

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 short sentences, front-loaded with the trigger condition and ending with the key limitation. Every sentence carries distinct information with no restated schema details in the body.

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, three-parameter lookup with no output schema, the description covers the essential decision inputs: what data exists, over what time horizon, and what the tool will not do. The one remaining gap is return-value expectations, e.g., whether omitting ride_id yields a ride-by-ride list.

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 date window and park_id shorthand guidance are already documented in the schema. The description echoes the same date-window fact rather than adding new meaning, and says nothing extra about ride_id beyond what the schema states. Baseline 3 applies when the schema does the heavy lifting.

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 and resource ('what Lightning Lane (or Universal Express) costs' and 'which rides have Lightning Lane return times available'), scoped to 'one supported park on a date'. This clearly separates it from sibling tools like parky_get_ticket_prices and parky_get_waits without needing to name them.

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 trigger conditions are given: a visitor asking about cost on a date, or about current return-time availability and how soon. It also states a capability boundary ('Parky cannot buy or book Lightning Lane'), which is a useful when-not signal. No alternative sibling tool is named for standby waits or general ticket pricing, so routing is implied rather than fully specified.

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