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

Goes well beyond the readOnly/openWorld annotations: it discloses per-source freshness (Forest Service refreshed every 6 hours), that California State Parks supplies no status, that 'not listed' means unknown rather than closed, and licensing/attribution constraints. That is exactly the kind of trust-calibration context annotations can't carry.

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?

Front-loaded with the core purpose and result fields, then the caveats; every sentence (including the licensing note) carries real information. Slightly dense for a single paragraph, but no filler.

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 does the work of describing return values (distance, open today, booking link). Combined with the freshness and licensing caveats, an agent has everything needed to call and interpret the result correctly.

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 0%, so the description carries the burden. It clarifies lat/long as a point and links the output to open-today status, but never explains limit, max_km (the search radius), or the open_today_only filter — the three parameters most likely to be mis-set.

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 ('campgrounds nearest a latitude/longitude') and names the three source datasets, so the agent knows exactly what it retrieves. It distinguishes itself from campgrounds_search only implicitly, via the geo-radius framing, rather than naming the sibling outright.

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 'nearest a point' framing implies when to reach for it (a location-based lookup), but there is no explicit when-to-use/when-not or reference to campgrounds_search or campgrounds_get_status as alternatives. Usage must be inferred from the sibling names.

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