ncloud_get_contract_usage_list

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds the 3-month window constraint and names the returned fields, which is useful, but there is no output schema and it does not describe pagination or the format of the returned usage details.

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?

Two sentences, front-loaded with the action and followed by the return payload and constraint. No filler, though the return-value sentence is somewhat generic.

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 12-parameter read-only query with no output schema, the description covers what is returned at a high level and the range limit. It falls short on the one thing most needed here: disambiguating from the sibling _by_daily variant and clarifying whether results are aggregated per contract or per day.

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 12 parameters (including enums for contractStatusCode and productItemKindDetailCode) are already documented in the schema. The description only restates the month-range constraint, adding little beyond the schema; baseline 3 is appropriate.

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 specific verb and resource ('Get contract usage list') and elaborates that it returns usage details per contract with metering type, usage quantity, and service period. However, it does not distinguish itself from the near-identical sibling ncloud_get_contract_usage_list_by_daily, leaving the agent to guess between the two.

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 notes a max 3-month range, but gives no when-to-use guidance, no exclusions, and never mentions the obvious alternative ncloud_get_contract_usage_list_by_daily or ncloud_get_contract_summary_list. The agent gets no routing help.

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