ncloud_kms_sign

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

The annotation readOnlyHint=true already communicates the non-mutating nature. The description adds useful constraints (8KB data limit, RSA2048/ECDSA key types) that are not in annotations. However, it does not disclose the return format or any error behaviors, which is a gap since there is no output schema.

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 exactly two sentences, front-loaded with the core action and immediately followed by a key constraint. Every word earns its place; there is no redundant or vague language. It is concise and well-structured for quick agent parsing.

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?

The tool is simple (2 required params, both documented in schema) and annotations cover the read-only safety profile. However, the absence of an output schema means the description should have explained the return value or signature format, which it does not. The missing output detail prevents a higher score, though the basic operation is clear.

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%, with both data and keyTag having descriptions. The description repeats the '8KB' limit already present in the data parameter's schema description, adding no new parameter semantics. Thus, it does not go beyond what the schema provides, justifying the baseline score.

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's purpose: 'Generate a digital signature for data (up to 8KB)' with a specific verb and resource. It also adds a key type constraint (RSA2048 or ECDSA), which helps narrow scope. However, it does not explicitly differentiate from sibling tools like ncloud_kms_verify or ncloud_kms_encrypt, so it does not fully meet the highest bar.

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?

No guidance is provided on when to use this tool versus alternatives. The description only states what it does and a key type constraint, not any preconditions (e.g., needing a compatible key) or exclusions. There is no mention of when to prefer sign over verify or other cryptographic operations.

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