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

No annotations are provided, so the description carries the full behavioral burden, and it discloses nothing: not that this is a pure read/transform operation, not that all five crypto inputs are functionally required despite zero declared required parameters, and not what happens on authentication-tag failure.

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?

It is short, but the brevity is pure redundancy — the entire description duplicates the name rather than front-loading any useful information. No sentence earns its place.

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?

A five-parameter cryptographic operation with no annotations, no output schema, and no required-parameter declarations needs the description to explain input requirements and failure modes. None of that is present.

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 100%, so the baseline is 3 even though the description adds nothing about iv, key, tag, secret, or ciphertext. The schema's own placeholder text ("Iv to process") is weak, but per coverage rules the schema is doing the documented work.

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 is a literal restatement of the tool name: "Decrypt Aes256gcm: Decrypt Aes256gcm". It names a verb and resource, but adds no scope, no input expectations, and does not distinguish itself from the sibling x402-encrypt-aes256gcm or any other decrypt utility.

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?

No guidance whatsoever on when to use this tool versus alternatives, what preconditions exist (e.g. key/iv/tag must come from a prior encrypt call), or what inputs are invalid. An agent gets zero routing help.

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