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

Adds real context beyond readOnlyHint=true: it discloses that owner badges held by the account are auto-resolved into a single proof, that invalid operation combinations are rejected rather than silently produced, and that the output is a manifest for the user to sign in their wallet. No contradiction with the read-only hint, since the tool composes rather than submits.

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 short sentences, front-loaded with the core action, then behavior, then the return contract. Every sentence adds information and there is no filler.

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?

Given no output schema, the description correctly states the return value (a signable manifest) and the failure mode (rejected combinations). It leaves some gaps for a builder tool — whether the built manifest still needs validate_transaction_manifest or preview_transaction, and any network-specific caveats — but the essentials are covered.

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%, so the per-parameter semantics are already documented, including the enum values and the note that field names come from list_validator_operations. The description only reinforces that badges are resolved from the signing account; it adds nothing about the 1-20 operation bound or how the operations array interacts with the single proof.

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?

Names a specific verb and resource ('Builds one transaction manifest') plus the input domain ('validator operations'), which cleanly separates it from the other build_* manifest tools (deploy, NFT, pool, DEX). It does not, however, name a competing sibling such as build_manifest_from_template that an agent might otherwise pick.

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?

'One or more validator operations' implies the domain of use and 'Refuses combinations the ledger would garble' signals a precondition, but there is no explicit when-to-use / when-not-to-use guidance and no pointer to list_validator_operations or validate_transaction_manifest (both only implied by the schema).

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