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

Annotations already declare destructiveHint=true and idempotentHint=true, so the destructive nature is covered. The description adds the scoping to 'the authenticated user' and clarifies the date/event format, which is useful context. However, it does not describe side effects beyond deletion (e.g., irreversibility), but annotations cover the core safety profile, keeping this at a baseline acceptable level.

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 short sentences with zero filler. The primary action and scope are front-loaded, and the parameter details are stated efficiently. 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?

Given the tool's simplicity, presence of an output schema, and annotations covering idempotency and destructiveness, the description is sufficient. It communicates the exact action, required parameters, and user scope. Minor omissions like error handling or idempotency behavior are already implied by annotations, so no critical information 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 description coverage is 100%, and the description repeats the parameter formats ('date is YYYY-MM-DD. event is flowstart or flowend') exactly as the schema does. It adds no new meaning beyond what the schema already provides, so the baseline 3 for high coverage 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?

The description states a specific verb ('Delete') and resource ('menstrual-cycle start or end mark'), and the title reinforces this. It clearly distinguishes from siblings like save_flow (which creates/updates) and delete_event (which targets calendar events). An agent can immediately tell what this tool does.

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 clarifies that it operates on the authenticated user's data and specifies the required parameters. It does not explicitly name alternatives or when-not-to-use, but given the sibling tools (save_flow, get_flows), the context is fairly clear. It provides sufficient guidance for correct invocation without ambiguity.

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