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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds meaningful behavioral context beyond that: the tool is 'non-custodial' and builds an 'unsigned transaction,' so the agent knows nothing is broadcast or mutated. It also discloses default behavior when ids is omitted.

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?

Four short, information-dense sentences with no filler. The most important qualifier ('v4 only') and the core purpose are front-loaded, and the v3 clarification is placed at the end where it serves as useful extra context.

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?

The description covers purpose, version scoping, non-custodial behavior, default claim-all behavior, and the v3 alternative, which is sufficient for invoking the tool correctly. It does not describe the exact output structure, but the phrase 'build an unsigned transaction' conveys the key return concept and there is no output schema.

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 schema already documents ids, user, chainId, and version. The description adds a useful conditional relationship—that chainId can be omitted when ids is omitted because the chain is discovered—but most parameter meaning is already present in 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 begins with 'v4 only' and states a specific action: 'Build an unsigned transaction to claim a wallet's V4 rewards.' This clearly identifies the verb, resource, and scope, and the wording distinguishes it from get_user_rewards and other prepare_* siblings.

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 explicitly scopes usage to v4 and explains the v3 alternative: 'There is no v3 equivalent because a v3 claim needs no second call: get_user_rewards already returns the transaction.' It also clarifies when to omit ids, telling the agent to claim everything when no ids are supplied.

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