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

Adds substantial context beyond the annotations: output is UNSIGNED tx bytes simulated against mainnet, the tool is non-custodial and never moves funds, content resembling a secret is rejected, and the fee is paid in WAL by the caller. This is exactly the behavioral detail an agent needs before invoking a tx-building tool.

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?

The actionable content is front-loaded and efficient, but the trailing 'Spot only, no leverage. Education only, not financial advice.' sentences are boilerplate that does not help an agent select or call the tool. Roughly a third of the text is non-functional.

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, so the description carries the return burden and does so reasonably (blob_id plus unsigned tx bytes). Combined with the refusal behavior and the pointer to walrus_store_guide, an agent has enough to act, though the epochs parameter remains unexplained.

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 only 33%: 'sender' is documented in the schema and 'content' is loosely implied by 'public text (receipt/note)'. The description adds no guidance for 'epochs' (range 1-53, default 3), leaving one of three parameters undocumented in both places.

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 (build) and resource (Walrus register-blob tx), names the payment asset (WAL), and declares the primary return value (blob_id). It is easily distinguished from sibling builders like build_swap_tx or build_bm_deposit_tx, which target entirely different protocol actions.

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 the follow-on step explicitly ('Then upload+certify locally (see walrus_store_guide)'), routing the agent to the correct companion tool. It also states an input precondition ('Refuses content that looks like a secret'), but never spells out when-not-to-use against siblings such as read_walrus_blob.

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