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

The annotations only declare readOnlyHint and openWorldHint, so the description carries most of the behavioral burden. It does this well: it says the output is the approvals plus the factory deployment call plus the index's predicted address, which shows that the tool builds transactions rather than executing them and keeps the description consistent with readOnlyHint. It does not mention whether the calls must be signed in a specific order or what happens if the predicted address is already deployed, so that is 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?

Three tight sentences with no filler. The core action and prerequisite come first, followed by the mechanism that sets the weights, and the return payload is stated last. Nothing is repeated, and every sentence provides information.

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?

There is no output schema, so the description rightly explains the return payload: approvals, factory call, and predicted address. Combined with 91% schema coverage on 11 parameters, the agent has enough to call the tool correctly. It does not cover edge cases such as the asset-count limit or fee bounds, but those are documented in the 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 coverage is 91%, so the schema already documents most parameters. The description adds meaning beyond the schema by explaining that the per-token seed amounts determine the basket weights and that initialShares is tied to those amounts. It also clarifies the seed-and-hold relationship for the wallet parameter. It does not clarify the fee parameters, mandate, or auctionMinutes beyond what the schema already says, but that is acceptable.

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 gives a concrete verb and resource: it launches a new index fund, defines how the wallet seeds the basket with tokens, and describes what the tool returns. An agent can distinguish it from sibling tools that buy, sell, or query indexes. It does not explicitly contrast with register_index or build_buy_index, so it falls just short of a 5.

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 states the main prerequisite: the wallet must already hold each basket token. It also states that the wallet receives initialShares shares and that seed amounts set the weights. It does not say when to choose this tool over register_index or other siblings, and it gives no exclusions or failure conditions such as running out of tokens or hitting the 20-asset cap.

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