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

Annotations are minimal (readOnlyHint=false, idempotentHint=false, destructiveHint=false), so the description carries the load and does so well: it explicitly states the server never signs and never holds keys, describes the 98/2 atomic split with no escrow, and lists exactly what the caller receives. This is materially richer than the annotations and directly shapes how an agent must act (sign externally, then submit).

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-loaded with the core action, then return values, then the signing model and split mechanics. Every sentence carries information, though the split is described twice ('98/2 split preview' and 'splits 98% ... 2%'), which is mild redundancy.

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?

With no output schema, the description compensates by enumerating the return values (Tips contract address, selector, hex calldata, exact HBAR value, split preview) and explaining the signing model. An agent has everything needed to invoke it correctly and act on the result.

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% — both parameters are documented, including the 'must be registered on-chain' constraint on recipient. The description adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 tipPage calldata for a tip to a blockpage') and immediately names the return payload. An agent can distinguish it from siblings like quote_tip (pricing only), prepare_purchase, or verify_tip (post-hoc confirmation) 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?

Gives a clear constraint and workflow: 'HBAR only (token tips need a human wallet)' tells the agent when this tool is NOT applicable, and 'Verify afterward with verify_tip — proof-of-payment reviews require a settled tip' names the follow-up tool and its condition. It stops short of contrasting with quote_tip as a preview alternative, so it is strong context without full alternative routing.

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