aes_decrypt

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

No annotations are provided, so the description must carry the behavioral burden. It only mentions the input format and the encryption algorithm, but omits output format, error handling, key requirements, and any side effects. This is minimal disclosure for a decryption tool.

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 with a PRO usage note, front-loaded with the purpose. It contains no unnecessary words and is easy to scan.

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, and the schema covers parameters, but there is no output schema or annotations. The description does not state the return value or failure behavior, which is a notable gap. It is adequate for a basic tool but incomplete.

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%, with both 'key' and 'encrypted' having clear descriptions. The description adds no new parameter semantics beyond what the schema already states, so the baseline of 3 is appropriate.

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 function: 'Decrypt AES-256-CBC encrypted text.' It specifies the algorithm and mode, and 'Expects hex-encoded input from aes_encrypt' ties it to its sibling tool, distinguishing it from other crypto utilities.

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 implies when to use it by stating that input comes from aes_encrypt, providing a clear prerequisite. It does not explicitly mention alternatives or when not to use it, but the counterpart relationship is evident from the sibling context.

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