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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context beyond the annotations: the data source (Recreation.gov), the kinds of matches included, and the specific return fields (IDs, names, types, phone/email, coordinates). This helps an agent predict the result content without an output schema.

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?

The description is front-loaded with the core purpose, then enumerates filter dimensions and return fields in compact phrases. The example call is a high-value addition and takes one line. No sentence is wasted or redundant with the 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 nine optional parameters and no output schema, the description covers the essential context: what is searched, how to filter, what the result contains, and a working example. It does not explicitly mention pagination or the optional _apiKey in prose, but those are already documented in the fully covered schema, so the missing prose is a minor 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 coverage is 100%, which establishes a baseline of 3. The description adds value by grouping the nine parameters into meaningful filter categories (name/keyword, state, activity, geographic radius) and by providing a concrete example call. This goes just beyond the schema's individual descriptions to show intended combinations.

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 well-scoped resource: US federal recreation facilities on Recreation.gov, with facility types enumerated. The description also lists filter dimensions and return fields, so an agent can identify what this tool does without opening the schema. It distinguishes itself from sibling search_recareas by focusing on facilities rather than areas.

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 description makes it clear this is a search tool with filters, but it provides no explicit guidance about when to choose it over sibling tools such as get_facility, list_campsites, or search_recareas. No exclusions or alternative routing are given, so the agent must infer the appropriate context from the general search wording.

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