ncloud_get_contract_demand_cost_list

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

The annotations already declare readOnlyHint=true, and the description adds useful behavioral context beyond that: it specifies the max 3-month range limitation and what the returned list includes (usage, pricing, discounts). It does not elaborate on pagination defaults or output structure, but the safety profile is covered by annotations, so the extra period/return details are sufficient.

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 description is two sentences, front-loaded with the verb and resource, then adds return details and the period limit. No redundancy or filler; each sentence contributes actionable 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 read-only list tool with 11 parameters and no output schema, the description gives the essential context: contract-level scoping, period limitation, and output categories. It does not describe pagination defaults or full output structure, but the schema covers parameter details, and the description suffices for understanding the tool's role. Slight gap on differentiating from similar cost-list siblings, but that is not critical for completeness.

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 all parameters (startMonth, endMonth, pageNo, etc.) have descriptions in the schema. The tool description does not add any additional parameter-specific meaning; it only references the period constraint already present in the schema. Baseline 3 is appropriate since the schema does the heavy lifting.

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 clearly states the tool gets a 'contract-level billing cost list' with a specific verb and resource scope. It details the return contents (usage quantities, pricing, discount amounts) and period constraint, distinguishing it from generic demand cost lists or product-level lists.

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 provides clear context: it's for contract-level billing costs within a specified period (max 3 months). It does not explicitly mention alternatives or when-not-to-use, but the contract-level focus is evident, giving implied guidance that this is for contract scoping rather than broader cost queries.

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