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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely new context — that results can be truncated and that displayTime.label should be preferred for timed events in the household timezone while startAt/endAt are UTC-style instants. However, it says nothing about result ordering, default limit, or what a truncated response looks like.

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 front-loaded sentences with no filler; the 'Use this when' condition leads and the timezone caveat follows. The second clause of sentence one ('narrow a truncated result') is slightly compressed but still earns its place.

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 7-parameter, zero-required, read-only search tool with a full output schema and complete annotations, the description covers purpose, trigger conditions, and the main interpretation pitfall (timezone handling). Only minor gaps remain around pagination/truncation mechanics, which are partly covered by the limit parameter in the schema.

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%, so every parameter is already documented (patterns, lengths, date formats), which sets the baseline at 3. The description gestures at the searchable facets but does not map them to specific parameters or clarify interactions such as query vs locationQuery or startDate vs endDateExclusive.

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/find) and resource (events) plus the dimensions searchable — text, person, contact, date. It does not explicitly distinguish itself from siblings like get_event or get_schedule, but the resource+verb combination makes the function clear.

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?

Opens with an explicit 'Use this when...' clause and adds a concrete workflow condition ('narrow a truncated result'), which tells the agent when this tool is the right follow-up call. No exclusions or named alternatives (e.g., use get_event for a single known event), which keeps it at 4 rather than 5.

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