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

Annotations already declare non-read-only, idempotent, non-destructive. The description adds the odd claim that "a plan is live as soon as it is made," which muddles rather than clarifies what activation actually changes (does it replace an existing active plan for that week?). No side effects or preconditions are disclosed.

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?

Only two sentences, so length is fine, but the second sentence is speculative filler that undermines confidence in the tool's purpose instead of clarifying it.

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 state-changing, non-read-only tool with no output schema, the description should say what state changes and what happens to any previously active plan. Instead it leaves the core effect ambiguous.

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 100% and the single parameter is fully documented as "any date in the week." The description's "the week that holds weekStart" restates that resolution rule without adding new meaning, so the schema carries the weight.

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 conveys that this activates a week's plan ("the one that counts"), but the phrasing is indirect and never uses a clear verb like "activate". It does not distinguish the tool from the closest sibling, plan_week, leaving the agent to guess which one to call.

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?

"This matters only when the household asks for it" is the sole usage cue, and it is vague and unactionable – an agent has no way to detect a household request. No alternative (plan_week, replan_open_days, get_planning_status) is named or excluded.

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