List persons in zone

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

With readOnlyHint and idempotentHint already declared, the description adds substantial behavioral context: it reads the zone's own `persons` attribute, explains the fallback path when that attribute is absent, and flags the zone.home special case where Home Assistant always reports 'home'. This is real implementation-detail disclosure beyond the annotations.

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 primary purpose, then conditions, then 'Use when' and 'Returns'. The middle paragraph on the persons-attribute fallback is dense but informative; slightly longer than strictly needed for a one-parameter read tool.

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?

Given an output schema exists (so return shape enumeration carries less burden), the description still summarizes the returned dict fields and the empty-list edge case, and explains the resolution order for identifying zone members. For a read-only single-param tool, this is complete.

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% and the schema documents the bare-id auto-prefix behavior; the description adds the fallback semantics tied to the zone_entity_id (that a missing zone yields an empty list). It reinforces schema meaning rather than duplicating the format string, but adds limited new parameter-specific detail beyond coverage.

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 opens with a specific verb+resource+scope ('List person entities currently inside a given zone'), distinguishing it from sibling list tools like zones_list_zones and entities_list_entities. The 'currently inside' phrasing makes the temporal filter explicit.

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 provides an explicit 'Use when: checking who is currently inside a specific zone', which gives clear positive guidance. It does not name an alternative tool or an exclusion condition, so it falls short of 5.

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