aes_encrypt

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

With no annotations, the description carries the full behavioral burden. It discloses the encryption algorithm, the output format (hex-encoded IV + ciphertext), and the key hashing behavior. It does not mention potential errors or side effects, but covers the key functional behavior.

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 concise and front-loaded with the core verb and resource. However, the '[PRO — 3 trial uses left]' prefix is extraneous promotional content that does not help an agent understand the tool's purpose or usage.

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?

Despite lacking an output schema, the description explicitly states the return format (hex-encoded IV + ciphertext), which is sufficient for this two-parameter tool. The algorithm and key handling are explained, making the description complete for a simple encryption utility.

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 schema already documents both parameters. The description adds only a minor usage tip ('Use a strong key') and restates the key derivation behavior, providing limited additional semantic value 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 states a specific verb ('Encrypt') and precise resource ('text using AES-256-CBC'), clearly distinguishing it from sibling tools like aes_decrypt and hash. The algorithm and output format are explicit.

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?

Usage context is implied by the tool's name and encryption purpose, and it includes a practical tip about key strength. However, it does not explicitly contrast with sibling tools (e.g., aes_decrypt) or state when not to use this tool, making the guidance implicit rather than explicit.

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