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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is fully covered and the description carries a lighter burden. The description adds only the returned attribute set (loop, accessibility, type, reservable) and confirms the facility/query split; it says nothing about pagination, result caps, or empty-result behavior beyond what the schema's limit already states.

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 compact sentences, zero filler, with the capability statement front-loaded before the calling instructions. The second sentence is slightly dense with the two-branch instruction, but nothing is wasted.

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, three-parameter search tool with no output schema, the definition covers purpose, the two input modes, and the attributes of interest, and the annotations cover the safety profile. It is nearly sufficient; only sibling routing and paging behavior are absent, which are minor for this shape.

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 all three parameters (limit, query, facility_id) are already documented in the schema. The description restates the facility_id and query semantics at roughly the same level of detail as the schema, adding no new syntax, format, or precedence rules, 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 ("Search") and a precisely scoped resource ("individual campsites (sites within a campground)"), and clarifies the granularity with the parenthetical. It does not explicitly distinguish itself from siblings like recreation_search_facilities or recreation_search_recareas, so an agent must infer the campsite-vs-campground boundary.

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 useful routing between its own two input modes ("Provide facility_id to list sites ... or query to free-text search"), which is genuine usage context. However, it never says when to use this tool versus the sibling recreation_* search tools, nor any when-not condition, so guidance 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.