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

Annotations already carry the full safety profile (readOnlyHint, idempotentHint, destructiveHint=false, closed world), so the trailing 'Read-only' is largely redundant. The description does add genuinely non-structured behavior: events shown are only 'what members chose to share', a data-visibility/privacy nuance an agent could not infer from annotations or 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?

A single front-loaded sentence enumerating the payload, closed with a short safety note. Efficient and well ordered, though the long em-dash list makes the kind/field details slightly harder to scan than separate sentences would.

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 an output schema present, return values need no further explanation, and both optional parameters are fully specified in the schema. Scope, composition and read-only nature are covered; only the missing sibling-routing guidance keeps it from being 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 description coverage is 100%, and the schema already documents the YYYY-MM-DD week format, its default, and the household-name/householdId lookup. The description only echoes the one-week scope, adding little beyond the structured fields, 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?

A specific verb+resource ('the household calendar for one week') followed by an explicit inventory of what it contains: the household's own events, members' shared items, school days, and club sessions, each with date, time, title, who and kind. That composition is distinctive enough to separate it from personal-calendar siblings like read_schedule or events 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 description never states when to pick this tool over the many neighbouring read tools (read_schedule, events, list_upcoming, read_chores). Scope is implied by the weekly framing, but there is no explicit when/when-not or alternative routing guidance.

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