decrypt_message

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states the action (decrypts) and offers no details about error handling, key requirements, output format, or side effects. This is a significant gap for a tool that could fail on wrong keys or invalid input.

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 no fluff, front-loading the action and resource. It is appropriately concise for a simple operation, though it sacrifices depth for brevity.

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?

While an output schema exists, the description lacks essential context such as key format, error behavior, or any caution about invalid inputs. For a tool with two required parameters and no annotations, this is insufficient for confident invocation.

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?

The schema has 0% description coverage, so the description must explain the parameters. It does not mention encrypted_message or encryption_key at all, leaving the agent without any semantic guidance beyond the property names. This fails to add value over the schema.

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 states a specific verb (Decrypt), a resource (message), and explicitly ties it to the encrypt_message tool, which clearly differentiates it from its sibling. This meets the highest bar for purpose clarity.

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 gives a clear prerequisite: the message must have been encrypted with encrypt_message. This tells the agent when the tool is applicable, though it doesn't explicitly mention when not to use it or name the sibling as the encryption counterpart. Still, the context is clear enough to guide usage.

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