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

Annotations already declare readOnlyHint=true, destructiveHint=false and a closed-world scope, so the safety profile is covered. The description adds content those annotations cannot: the result is segmented by ticket/pass type, the horizon is capped at 7 days, and the data comes from Disney's and Universal's own calendars, which tells the agent how authoritative and how fresh the answer is.

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, both load-bearing: the first gives the trigger, the second gives the return shape and scope. The most decision-relevant information (when to use it) is front-loaded with no preamble.

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 tool with a fully documented 3-parameter schema and no output schema, the description supplies the missing return-shape context (segment granularity, 7-day window, data source). It does not cover failure cases such as an unsupported resort key or a date range with no published calendar, which is a minor remaining 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%, with the date format, the 1-7 day range and the resort keys (wdw, dlr, uor, ush) all documented in the schema. The description only loosely echoes this ('for up to 7 days', 'given dates', 'supported resort') and adds no new parameter guidance, so the 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 and resource ('get park reservation availability') and then defines exactly what gets returned: reservation/blockout status by ticket-or-pass segment. It is clearly distinguishable from adjacent siblings like parky_get_hours and parky_get_ticket_prices, which cover different visitor questions.

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?

The opening clause gives an explicit trigger: 'Use this when a visitor asks whether a park has reservations or blockout dates for a ticket or pass type on given dates at a supported resort.' That is a precise when-to-use condition scoped to a supported resort, though it stops short of naming an alternative tool or an exclusion case.

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