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

Annotations already provide readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds valuable domain-specific behavioral context: the message is origin- and account-bound, signing leads to permanent binding, and the operation involves no spending. This does not contradict the annotations.

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 short sentences front-load the main action and then add the two most decision-relevant caveats: no spending and permanent binding. There is no filler, redundancy, or restating of the title.

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?

For a simple two-parameter read-only tool with strong annotations and no output schema, the description is nearly sufficient: it states what is returned (a message to sign), the binding constraint, and the safety profile. It could be more explicit about the next step or which address is expected, but an agent has enough to invoke it correctly.

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 50%, with agent_key already described and address only given as a regex. The description partially compensates by indicating the wallet is operator-authorized, which maps to the required address, but it never explicitly names the address parameter or explains how the address and agent_key relate, leaving some inference required.

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 uses a specific action ('Get') and resource ('message to sign') with useful constraints: origin- and account-bound, and operator-authorized Base wallet. It clearly communicates that this is a message-fetch tool rather than a transaction or bind tool, though it does not explicitly name a sibling such as exchange_bind_wallet to differentiate from.

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 context is fairly clear: use this tool to get the exact message that must be signed with an operator-authorized Base wallet, emphasized by 'No spending' and 'Binding is permanent.' However, it does not explicitly state when to use this instead of related wallet/binding tools, nor does it give exclusions or alternative conditions.

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