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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the description is free to add domain context. It does: it discloses the informational boundary (no PII accepted) and a genuine caveat that a layover does not guarantee completion before departure, which an agent could not derive from structured fields.

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?

Four tight sentences, front-loaded with the purpose before the field clarification and constraints; no filler. The telegraphic fragments are efficient but slightly clipped, leaving some clauses to be inferred.

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 explanation tool with no output schema, the description covers what the rule addresses, the scope of situations, and what inputs are forbidden. It never hints at the form of the returned guidance, but the annotations and enum-driven schema make that gap minor.

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 0%, so the description must carry the parameter meaning, and it does the most important work: 'state is where care would take place, not home residence' disambiguates a field whose enum values alone would mislead. It also signals the situations covered (visitors, short stays, layover), loosely mapping to the situation enum values, though it does not define each enum member.

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 states a specific verb and resource: explain the physical-location rule that determines where care can take place, including visitor and short-stay cases. That is clearly distinct from siblings like check_service_availability or get_online_care_boundaries, though it never names an alternative to disambiguate explicitly.

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?

Usage is implied by the scope (visitors, short stays, layovers) and the description draws a hard boundary against sending address, travel dates, itinerary or personal information. However it never states when to pick this tool over the many sibling rule/eligibility tools, so routing remains inferential.

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