Recurring schedule

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered; the description's "no task is executed or calendar updated" largely restates that. Where it adds real value is the non-obvious disclosure that times float in the importing calendar's local time zone, which affects DST and cross-zone correctness.

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?

Three tight sentences: capability and outputs first, usage and non-effects second, the floating-time caveat last. Every sentence carries distinct information and there is no padding.

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?

An output schema exists, so return values needn't be explained, and the read-only/idempotent behavior is already annotated. The description covers purpose, non-effects and time-zone semantics, but omits the 20-task cap and the meaning of the owner field, which an agent may need to fill in a valid request.

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?

With only 50% schema description coverage, the description partially compensates by tying the tool to weekly/biweekly/monthly frequencies and minutes-based hour estimates. It says nothing about the opaque owner enum (delegate/keep/decide), day, monthday, or time, leaving the most ambiguous parameter undocumented.

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?

Names specific verbs and outputs: estimate monthly hours, return recurrence rules plus a complete RFC 5545 calendar. The scope is concrete and unusual enough to be distinguishable. However, it never references siblings such as cron_next_runs, which is the nearest alternate schedule-generation tool, so differentiation still requires opening schemas.

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?

"Use to prepare a schedule" gives a general context, but there is no explicit when-not or named alternative, and the sibling cron_next_runs covers adjacent ground without being mentioned. Usage is implied rather than routed.

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