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

With only readOnlyHint=true supplied, the description does add one genuinely useful behavioral fact: shares, liquidity, permissions and vault state are NOT validated here but must be established beforehand via agent discovery and wallet simulation. That tells the agent this is a plan/calldata builder rather than a validated execution path. However, the phrasing is terse and jargon-heavy, and it never states plainly that the output is an unsigned transaction or that the caller is responsible for the safety checks, so the disclosure is present but under-articulated.

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?

Two sentences, purpose front-loaded, no filler or marketing language. The second sentence is dense and slightly opaque ('direct agent discovery and exact wallet simulation'), costing a little clarity, but nothing is redundant.

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?

Six parameters at full schema coverage plus an output schema mean the description only needs to carry purpose and behavioral caveats, and it does both. The remaining gap is sibling disambiguation against prepare_morpho_vault_redeem and the other prepare_* withdraw tools, which would be cheap to add and would materially help selection.

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 every parameter including owner/recipient defaults and base-unit amount is already documented. The description reinforces that the amount is an exact underlying-asset figure rather than a share count, which is a meaningful disambiguation from redeem, but it adds no syntax or constraint detail beyond the schema. Baseline 3 applies.

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 names a specific verb and resource ('Prepare a direct Morpho Vault V2 withdrawal') and pins down scope ('exact underlying-asset amount from a fixed vault'), which implicitly separates it from the share-denominated sibling prepare_morpho_vault_redeem. It stops short of naming that sibling or stating the amount-vs-shares distinction explicitly, so an agent must infer the boundary.

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?

Usage is implied rather than stated: the 'fixed vault' and 'exact underlying-asset amount' framing suggests the vault address must come from discovery, and the schema points at get_morpho_vaults. There is no explicit when-to-use/when-not or a named alternative such as prepare_morpho_vault_redeem for share-based exits, so selection guidance is left to inference.

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