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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds valuable behavioral context: it explains that candle-lighting, havdalah and fast times are only included when a location is provided, and it lists the default event categories. It does not describe the output structure, but no output schema exists and the coverage is adequate for a read-only tool.

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, front-loaded with the core purpose, then a compact enumeration of event types. The usage instructions and defaults are packed into the second sentence without redundancy. Every word 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 tool with 27 parameters and no output schema, the description covers the essential decision points: how to specify the date range, the maximum span, the default event set, and the location-dependent behavior. It does not explain every parameter, but the schema handles those details. The description is sufficient for an agent to invoke the tool correctly in most cases.

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 78%, so most parameters already have descriptions. The description adds semantic value by clarifying the two usage modes (range vs year) and by summarizing which event categories are on by default (holidays, Rosh Chodesh, fasts, special Shabbatot, parsha). This goes beyond the schema, which lists each default individually.

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 clear verb and resource: 'List Jewish calendar events for a date range' and then enumerates the event types (holidays, Rosh Chodesh, fasts, etc.). It distinguishes itself from siblings like get_shabbat_times or get_parasha by covering the full calendar, not just one component. The scope is 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?

The description provides clear usage instructions: pick start+end or year (+ optional month), max range ~1 year, and explains defaults. However, it does not explicitly name alternative tools for narrower queries (e.g., get_shabbat_times for only candle-lighting), so the when-not-to-use guidance is implied rather than stated.

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