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

Goes well beyond the annotations (which only cover read-only/idempotent/destructive flags). It discloses that the server never signs or holds keys, that unassociated recipients get a PENDING airdrop that can be cancelled, that the sender pays all fees/rent, and that the return value is frozen bytes plus best-effort pre-checks.

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?

Front-loads the core action (build unsigned bytes) before secondary details, and each sentence earns its place by adding fee model, signing model, or routing context without 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?

For a multi-step prepare tool with no output schema, the description covers the return value (frozen bytes + pre-checks), the custody model, the fee model, and the pending-airdrop lifecycle — everything an agent needs to call and sequence it correctly.

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 token_id, recipients, sender_account_id, and the amount/serial_numbers split; baseline 3 applies. The description reinforces the amount-OR-serial rule and sender-pays semantics but adds no parameter syntax beyond 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?

States a specific verb and resource: 'Build the UNSIGNED HIP-904 TokenAirdropTransaction bytes' to distribute HTS tokens/NFT serials. It distinguishes itself from siblings by naming the routing target (check_pending_airdrops) and the sign/submit division of labor.

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?

Gives clear context (prepare a transaction for the sender to sign, no pre-association needed) and routes to check_pending_airdrops for a related step. It does not explicitly state when to prefer another prepare_* sibling or any prerequisites/exclusions, so it stops short of a 5.

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