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

With no annotations, the description must carry the behavioral burden. It usefully explains that Bitcoin witness assembly happens server-side and how refund preimages are omitted, but it does not disclose important broadcast behavior such as irreversibility, retry/idempotency semantics, confirmation behavior, or required permissions.

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 purpose is front-loaded in the first sentence, followed by chain and payload details. The second sentence is long and dense, especially the Bitcoin clause, but most of the detail is necessary given the untyped parameter.

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?

The description covers input payload formats well, which is important given the empty schema. However, with no output schema and no annotations, it leaves return values, success/failure behavior, and confirmation semantics undescribed, which are relevant for a transaction broadcast tool.

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 0%, so the description must compensate, and it does: it explains the chain enum and the chain-specific meanings of the untyped 'signed' payload, including EVM raw hex, Solana base64, and Bitcoin raw/PSBT forms. TRON is described only vaguely as 'the signed transaction object,' so it is not fully precise.

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?

Uses a specific verb, relay/broadcast, and resource, a transaction the caller signed, and clearly distinguishes this from build/preparation tools by emphasizing the payload is already signed. The chain set and signed-payload focus make the tool's job unambiguous.

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?

The description makes clear this is for submitting an already-signed transaction and references payloads coming 'from a build step,' which implies the build_* siblings are upstream. It does not explicitly state when not to use it or list the alternative build tools by name, so it is clear but not fully routing-aware.

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