vigenere_cipher

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

No annotations are provided, so the description carries the full burden. It only states basic functionality but does not disclose important behavioral traits such as handling of non-alphabetic characters, case sensitivity, or whether the cipher preserves case. This leaves significant gaps in transparency.

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, using three sentences plus a bulleted parameter list. It is efficient, though the parameter list could be integrated into the prose to reduce redundancy.

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 having an output schema, the description does not mention the return value (e.g., the transformed string). It omits details on edge cases and parameter constraints. For a tool with moderate complexity and zero schema description coverage, the description is 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 0%, so the description must compensate. It enumerates parameters with brief explanations (e.g., 'text — The plaintext or ciphertext string'), but these add minimal meaning beyond the parameter names and schema types. No details on constraints like key alphabetic characters or mode valid values are provided.

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 it encrypts/decrypts text using the Vigenère cipher with a keyword, which is a specific verb+resource combination. It effectively distinguishes itself from sibling tools like caesar_cipher or atbash_cipher by naming the specific cipher method.

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 says 'Use this for classical encryption using the Vigenère method,' which implies a context but does not explicitly state when not to use it or provide alternatives among siblings. There is no guidance on choosing this over other cipher tools.

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