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

Annotations already declare destructiveHint=true and idempotentHint=true, and the description adds the crucial detail that the call REPLACES the existing skip list rather than appending, plus the clearing behavior and the required prerequisite read. It explains what gets destroyed, which annotations only flag.

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 core action, then motivation, then the destructive warning, then a clean Args block. No filler sentences; each part 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?

An output schema exists so return values need not be described, and for a two-parameter mutation the description covers the replacement semantics, the prerequisite, the format, and the clearing case. Nothing an agent needs to call it correctly is missing.

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 0%, so the description must carry parameter meaning, and it does: reminder_id is sourced 'from list_reminders', skip_dates is specified as local dates in 'YYYY-MM-DD' form with a concrete example array. That fully compensates for the undocumented schema.

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 states a specific verb (Set) and resource (skip dates for a recurring reminder's no-call days), which is clear and concrete. However, it never names or contrasts with the closest sibling, skip_next_occurrence, leaving some ambiguity about which tool handles one-off skips versus a full skip list.

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?

Explicitly frames when to use it (holidays, travel, a few-day pause) versus the alternative of deleting and rebuilding a reminder, and gives the prerequisite workflow: read existing skips with get_reminder first, and pass an empty list to clear. That is a complete when/when-not/alternative picture.

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