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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds genuinely new context: 'open' is derived from published schedules rather than live conditions, and results include site counts and reservation links. It doesn't cover pagination or result ordering, so it isn't exhaustive.

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 result content is front-loaded and the sibling routing caveat is placed last where it belongs.

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 usefully enumerates what comes back (open-today status, site counts, reservation links) and annotations cover the read-only profile. The missing radius/limit behavior is the only notable gap for a 5-parameter geo query.

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 must carry the burden. It clarifies the point-based latitude/longitude query and the open_today_only flag, but says nothing about limit or max_km, leaving the default 100 km radius and result cap (a 5-param tool) unexplained.

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 ('NPS campgrounds nearest a point') with the scope of the query, and explicitly separates itself from nationalparks_get_park_status. An agent can distinguish it from both siblings without opening a schema.

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 clause 'Schedules only: check nationalparks_get_park_status for current alerts' names an alternative and the condition that selects it, which is explicit when-not guidance. It stops short of the full 5 because it never addresses when to use this versus nationalparks_search_parks.

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