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

Annotations already establish readOnly/non-destructive/closed-world, so the bar is low; the description adds useful context beyond them: single-park scope, a 30-day horizon limit, and the epistemic nature of the result ('a forecast and range, not a guarantee or a live wait'). It does not mention failure modes for unsupported parks or how a range is expressed.

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, zero filler, with the usage trigger and scope front-loaded. Every sentence carries distinct information (trigger, prerequisite, output nature).

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 compensates by characterizing the return ('forecast and range, not a guarantee or a live wait') and by covering scope, horizon, and the ID prerequisite. It is complete enough to call correctly, though it says nothing about behavior for unsupported parks or how a multi-day range is returned.

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 schema already defines date, days, and park_id; baseline would be 3. The description adds meaning by reinforcing the park-local time zone framing and the 'resolve the park ID first' dependency, which signals that park_id is a foreign key resolved via parky_find_experience rather than an arbitrary string.

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 concrete operation on a concrete resource: a crowd forecast for one supported park over the next 30 park-local days, and clarifies the output is a forecast/range. It partially rules out a sibling by contrasting with a 'live wait' (parky_get_waits), but it does not explicitly differentiate itself from parky_get_hours or parky_find_experience.

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 ('when a visitor asks how crowded one supported park may be') plus a prerequisite ('Resolve the park ID first'), and bounds the horizon to 30 park-local days. It stops short of naming the alternative tool to use for live waits, so the when-not is implied rather than explicit.

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