joltsms_release_number

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

No annotations are provided, so the description carries the full burden and does so well: it discloses that paid numbers persist until end of billing period, that auto-renewal is disabled on release, and that unpaid initial checkouts are canceled immediately. The timing semantics are the key behavioral trait here and are clearly stated.

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?

The purpose is front-loaded, which is good, but the paid-vs-unpaid timing rule is stated twice — once in the first paragraph and again in the final sentence — making it redundant. Trimming the duplicate would leave a tighter definition.

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 single-parameter, annotation-free tool with no output schema, the description covers the important lifecycle semantics (release timing by billing state). It does not say what happens to the number or its messages after release, but nothing an agent needs to invoke 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 description coverage is 100% and the description repeats the same sourcing guidance already in the schema's subscription_id description. It adds no new syntax or format detail, so the baseline 3 for full schema 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 opens with a specific verb and resource: 'Cancel/release a rental.' An agent can immediately tell this is the inverse of a provisioning/rental tool. It does not explicitly name a sibling it is distinct from, but the action is unambiguous.

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 tells the agent where the required ID comes from (joltsms_list_numbers, or the pending subscription ID from an unpaid 3DS checkout), which is useful routing context. However, it never states when NOT to use this tool or contrasts it against siblings like joltsms_update_number, leaving the choice to inference.

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