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

Annotations only declare readOnly=false and destructive=false; the description goes well beyond them by disclosing proration on the first new-plan bill, pending-cancel/pending-active state changes, admin+member email notifications, a per-tool confirmation default, an outbound-impact warning, and the API key requirement. This is exactly the extra behavioral context annotations cannot carry.

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 modes, side effects, and operational caveats in a logical order with no filler. It is dense and slightly long, but essentially every sentence carries distinct information.

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 mutating, open-world tool with no output schema, the description covers purpose, both modes, billing effects, notification side effects, confirmation policy, and auth needs — everything an agent needs to invoke it correctly without guessing.

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% so the schema documents all five params, but the description meaningfully enriches the 'when' enum by explaining the concrete consequences of each value (immediate end + prorated fees vs pending cancel/active). waive_setup_fee and the ID params are left to the schema, keeping this just below a 5.

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?

States a precise verb+resource+scope: 'Move a member from one recurring plan to another, now or at the next bill date.' This clearly distinguishes it from its PushPress siblings like pushpress_cancel_member_plan and pushpress_pause_member_plan, and it names the two operating modes up front.

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?

Gives clear context for choosing between the two modes ('now' vs 'next_bill_date') and states the constraint that it works only for recurring plans. It does not explicitly tell the agent when to prefer this over cancel_member_plan or pause_member_plan, so it stops short of full when/when-not guidance.

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