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

With readOnlyHint=true already declaring the safety profile, the description adds real context beyond annotations: it resolves the owner badges the account holds, composes a single proof across all operations, rejects combinations 'the ledger would garble', and states the output is an unsigned manifest for the user to sign in their wallet. That is a meaningful disclosure of pre-signing behavior, though the refusal condition remains vague ('garble').

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 sentences, front-loaded with the core action and no filler. The middle sentence ('Refuses combinations the ledger would garble') is colorful but carries a real constraint; only the wallet-signing clause borders on the obvious.

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?

No output schema exists, and the description compensates by explaining that the return value is a manifest intended for user signing rather than for direct submission. Combined with the 100%-covered input schema and the badge/proof composition note, an agent has enough to call it correctly; the exact failure semantics of rejected combinations is the only notable gap.

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% and the nested operations array is fully documented in-schema (kind enum, values shape, minItems, pointer to list_validator_operations), so the baseline is 3. The description adds only the aggregate notion of 'one or more validator operations' and does not clarify field-level semantics or the account/network roles beyond what the schema already says.

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?

Specific verb ('Builds') plus specific resource ('one transaction manifest out of one or more validator operations'), which cleanly separates it from the other build_*_manifest siblings that target tokens, NFTs, packages, faucets and templates. The scope (validator operations only) is stated up front, so an agent can route correctly without opening the schema.

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 by the resource ('validator operations') and by the schema's reference to list_validator_operations, but the description never states when to prefer this over build_manifest_from_template or when it should be avoided. No explicit prerequisites or alternatives are named, leaving the agent to infer the selection rule.

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