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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds the return contract (field names) that no output schema provides, which is genuinely useful; it does not mention whether the message/nonce expires or requires a live socket, a minor 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 opens with the trigger ('Use to start a wallet session'), then lists the return fields and the next step with zero wasted words.

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 one-parameter flow-initiation tool with no output schema, the description supplies the return shape and the follow-up call, which is enough to use it correctly. Expiry/lifetime of the nonce and message is the only notable omission.

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% and the schema already documents the wallet param including its 0x pattern and the 'never a key or seed' warning. The description does not add any input-parameter meaning beyond that, so the baseline 3 is appropriate.

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 action (produce a wallet signing message) and enumerates the exact return payload shape {wallet, ts, nonce, message}. It implicitly distinguishes itself from memeswap_session_open by describing the two-step flow, though the phrase 'start a wallet session' is slightly ambiguous since session_open is what actually opens the session.

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?

It gives explicit sequencing: call this first, have the wallet personal_sign the message, then pass the signature to memeswap_session_open. The alternative/next tool is named, leaving little to infer, but there is no statement of when this step can be skipped or what preconditions exist.

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