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

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly lists the output fields (public_key_in_pem, private_key_in_pem, curve), mentions optional password protection for the private PEM, and details each curve's capabilities. This provides a solid picture of what happens when the tool is called, though it doesn't cover edge cases like error behavior or key format 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?

The description is well-structured with clear sections for curve list, parameters, output, and capability matrix. Each line serves a purpose, and the format is front-loaded with the primary action. It is dense but not bloated, efficiently conveying necessary 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?

Given the tool has no output schema, the description compensates by explicitly listing the three output fields. It also covers all curve options, capability restrictions, and parameter details. The tool's complexity is fully addressed, and the description provides enough information for an agent to invoke it correctly without ambiguity.

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%, so parameters are already documented. The description adds value by explaining the meaning of the curve parameter through the capability matrix and clarifying that private_key_password provides PEM encryption protection. This goes beyond the raw enum values in the schema.

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 begins with '生成 ECC 密钥对' (generate ECC key pair), which is a specific verb+resource statement that clearly identifies the tool's purpose. It distinguishes from sibling tools like ecc_key_sign, ecc_key_verify, and ecc_key_exchange, which perform subsequent operations rather than generation.

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 a capability matrix mapping each curve to its supported operations (e.g., ED25519 only signing, X25519 only ECDH), giving clear context on when to use each variant. While it doesn't explicitly state 'use this instead of generate_rsa', the matrix effectively guides curve selection, which is the main usage decision for this tool.

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