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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. Beyond that, the description adds genuinely useful behaviour: a 30-day measurement window, the specific metrics returned, and the sort order. It does not say how missing or sparse outage data is handled, which is the main residual gap.

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, zero waste: the trigger condition leads and the payload description follows. Every clause carries either usage or return-value information, and nothing repeats the annotations or schema.

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 must explain return values and does so by naming the three metric families and the ordering. For a read-only two-parameter reporting tool this is close to sufficient; only the handling of parks or rides with no outage history is left unstated.

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 coverage is 100%, and the park_id description is unusually thorough (accepts keys, canonical IDs, names, and shorthands with no lookup). The tool description itself adds no parameter meaning; the only extra information, 'least reliable first' ordering, describes output rather than input. Baseline 3 applies since the schema does the work.

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 uses a concrete verb-plus-resource ('Returns 30-day uptime percentage, outages per day, and average and longest outage') and frames the resource as ride reliability, which an agent can distinguish from a raw outage list. It does not name the neighbouring parky_get_ride_outages or parky_get_ride_history tools, so the distinction is inferred from the aggregate 30-day framing rather than stated.

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?

'Use this when a visitor asks how often a ride breaks down or which rides at a park are least reliable' gives a clear trigger condition tied to user intent. It stops short of exclusions — it never says to use the outage-list or history siblings for raw event detail — so the agent must infer that boundary.

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