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

Annotations already declare readOnlyHint, non-destructive, and closed-world, so the safety profile is covered. The description adds genuine value beyond that by disclosing the data-fidelity behavior: facts vary per ride and missing facts are omitted rather than guessed, which tells the agent not to treat absence as a negative answer. It says nothing about result size or pagination, keeping 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, with the primary use case front-loaded and the caveat about missing facts placed after it. 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?

For a one-parameter read-only list tool with annotations and no output schema, the description covers when to call it and how to interpret gaps in the returned facts. It does not sketch what a ride entry contains beyond the comparison attributes, which leaves a small gap, but nothing essential to invocation is missing.

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?

There is a single parameter at 100% schema coverage, and the schema description already enumerates accepted forms (key, canonical ID, name, shorthand examples), so the description need not repeat it. The phrase 'one supported park' hints that unsupported parks are rejected, but no additional syntax or format meaning is added, making the baseline 3 correct.

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 verb and resource: returning every ride at one supported park, and it enumerates the comparable attributes (height requirement, length, speed, Lightning Lane). This separates it in spirit from the single-ride sibling parky_get_park_ride, though it never names that sibling, so the differentiation is implicit rather than explicit.

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 gives a clear triggering condition: use when a visitor wants all rides at one park, or wants to compare rides along the listed dimensions. There is no explicit when-not guidance or named alternative (e.g. for a single ride use parky_get_park_ride), so it stops short of the top band.

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