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

With no annotations, the description discloses important behavioral traits: plaintext length limits depending on key size and padding mode, output field names (cipher_data_in_hex, cipher_length), and a security best practice. It doesn't cover error handling or key validation, but it provides meaningful constraints beyond the 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 well-structured with labeled sections for parameters, length limits, output, and security advice. Every sentence carries necessary information without unnecessary verbosity.

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?

Since there is no output schema, the description lists output fields and provides length constraints and security advice. It is largely complete for an encryption primitive, though it could mention potential errors or key validation steps.

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?

The schema already covers all three parameters with descriptions, so the baseline is 3. The description restates parameter names and adds the length-limit context for plain_data_in_hex, but it does not significantly enrich meaning beyond 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 clearly states 'RSA 公钥加密' (RSA public key encryption), which is a specific verb+resource. It distinguishes from sibling tools like rsa_decryption, rsa_sign, and rsa_verify by explicitly indicating public-key encryption.

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 purpose line makes it clear this tool is for encryption, and the security recommendation to prefer OAEP over PKCS1v1.5 provides parameter-level guidance. It doesn't explicitly mention alternatives like rsa_decryption, but the context is unambiguous and no exclusions are stated.

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