decrypt_attachment

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

No annotations provided, so description bears full burden. Discloses that it is read-only on Signal data and writes a decrypted copy to a temporary directory. Adds important safety and side-effect information beyond basic decryption.

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?

Three sentences covering purpose, parameter source, and usage context. No redundancy, well-structured, and front-loaded with the core action.

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 moderate complexity (2 parameters, output schema exists), the description covers purpose, parameter sourcing, safety behavior, and usage timing. No obvious gaps for an agent to correctly select and invoke the tool.

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% with detailed descriptions. Description adds context on the origin and nature of the parameters (from attachment metadata, base64-encoded key structure), which aids correct invocation beyond schema 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?

Clearly states verb ('Decrypt'), resource ('locally stored Signal attachment'), and outcome ('return the path to the decrypted file'). Distinct from siblings which involve chat activity, status, lists, and messages.

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?

Explicitly states where the input parameters come from ('encrypted_path and local_key values come from attachment metadata in read_messages or search_messages') and advises using it after reading messages with attachments. No explicit exclusions, but context is clear.

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