decrypt_message

Does 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 state whether the operation is read-only, has side effects, or what happens on failure (e.g., wrong key). The only behavioral detail is the requirement for the same passphrase, which partially addresses input constraints but not the tool's overall safety profile. This is a significant gap.

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?

A single, front-loaded sentence with zero filler. It states the verb, object, and connection to the sibling tool efficiently, making it easy to scan and understand quickly.

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?

Given the tool's simplicity, full parameter coverage, and presence of an output schema, the description is mostly complete. It correctly identifies the key requirement and relationship to encrypt_message. However, lacking behavioral disclosure (e.g., error handling, purity) means it is not fully complete for an agent deciding to invoke it safely.

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 coverage is 100%, so each parameter already has a description. The tool description adds minimal semantic value beyond mentioning the key matches encrypt_message, which mirrors what the schema already states. This meets the baseline for full schema coverage but does not provide additional meaning.

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?

States a specific verb ('Decrypt') and resource ('a message'), and explicitly ties it to the encrypt_message tool, which differentiates it from the sibling. It is not a tautology; it names the exact operation and its counterpart.

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?

Clearly implies usage context by referencing encrypt_message, indicating it is the decryption counterpart. However, it does not explicitly state when not to use it or name alternative tools beyond the implicit sibling relationship. This is clear context but lacks explicit exclusions.

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