vigenere_encrypt

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

No annotations are provided, so the description carries full burden. It states the return format (JSON with ciphertext) and hints at key validation via the 'validate' parameter, but it does not describe behavior on validation failure, handling of non-letter characters, or limitations. The phrase 'validate key strength' is ambiguous.

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 short and front-loaded with the purpose. The Args and Returns sections are structured and easy to parse. One minor point: the validation description could be clearer, but overall it is appropriately sized for a simple tool.

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 with 3 parameters and a straightforward output. The description covers the main functionality but lacks details on edge cases (e.g., non-alphabetic input, key validation errors). Given the output schema exists, the description does not need to detail return values beyond 'JSON with encrypted ciphertext,' which is sufficient.

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 0%, so the description must compensate. It adds meaningful descriptions for all three parameters in the Args section (e.g., 'key: Encryption key (letters only)'), which clarifies constraints not in the schema (e.g., key must be letters). This adds significant value beyond type alone.

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 starts with 'Encrypt plaintext using Vigenère cipher,' which clearly states the tool's action (encrypt), resource (plaintext), and algorithm (Vigenère). This distinctly differentiates it from siblings like vigenere_decrypt, caesar_encrypt, and other crypto tools.

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 does not explicitly state when to use this tool versus alternatives like vigenere_decrypt or validate_key. It implies use for encryption, but lacks guidance on prerequisites (e.g., key must be letters only) or when not to use it. However, the context of sibling tools gives implicit differentiation.

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