Encrypt any message with a passphrase using AES-256-CBC. Provide the plain text and encryption key to produce secure ciphertext.
Encrypts a message using a passphrase
| Name | Required | Description | Default |
|---|---|---|---|
| message | Yes | The message to be encrypted | |
| encryptionKey | Yes | The passphrase used for encryption |
| Name | Required | Description | Default |
|---|---|---|---|
| encryptedMessage | Yes | The encrypted message (fomart: iv:ciphertext) |
Changes observed during successful MCP inspections.
v0.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must disclose behavioral traits. It does not explain what happens to the input, the output format, or any side effects. It also does not clarify that the encryption is symmetric and requires the same key for decryption, nor mention cryptographic details that an agent might need.
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 a single sentence that is concise and gets to the point. It is appropriately sized, though it could include more useful details without becoming verbose.
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?
An output schema is present, so the description need not explain return values. However, for a security-sensitive operation like encryption, more context is needed, such as algorithm details, key handling, or potential pitfalls. The description is minimal but not inadequate for a simple tool.
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 both parameters are documented in the schema. The description adds minimal semantics beyond the schema—it clarifies that 'encryptionKey' is a passphrase, which aligns with the schema's description. However, it doesn't provide additional context like key length or format requirements.
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: encrypts a message using a passphrase, with specific verb 'encrypts' and resource 'message'. It distinguishes from potential siblings by focusing on encryption, though no siblings are provided to compare against.
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 on when to use this tool versus alternatives, or any context such as typical use cases, prerequisites, or security considerations. The description simply states the action without indicating when it is appropriate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.