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

Annotations already flag destructiveHint=true and idempotentHint=false, but the description adds the crucial behavioral fact that this charges the customer's saved payment method and requires confirm=true, plus the underlying endpoint. It stops short of stating the double-charge risk implied by non-idempotency or what happens on a declined retry.

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 front-loaded sentences with a leading WRITE marker, the scope constraint, the side effect, and the prerequisite — no filler, and the most dangerous fact is surfaced early.

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 non-idempotent destructive write with no output schema, the description covers status precondition, time limit, payment side effect, and the confirm gate. Minor gaps remain (behavior on decline, whether the 30-day window is enforced or merely advisory), but nothing critical for correct invocation 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%, so subscription_id, confirm, and log_note are already documented in the schema. The description only reiterates the confirm=true requirement, adding no syntax or meaning beyond the schema; baseline 3 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 gives a specific verb (retry the renewal), the exact resource (a PAST-DUE subscription whose renewal failed), and a temporal scope (within the last 30 days). This scope constraint cleanly separates it from siblings like cratejoy_reactivate_subscription and cratejoy_skip_subscription_renewal.

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?

It states the precise condition that selects this tool (past-due status, failure within 30 days) and the confirm=true prerequisite. It does not name the alternative siblings (reactivate, skip) or when to prefer them, so it stops short of explicit routing.

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