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

Annotations already declare readOnlyHint and destructiveHint=false, and the description reinforces 'reads or computes only and changes nothing'. It adds useful cost/error context (400 uncharged on malformed input, $0.01/call, first 25 free, failed calls free), but this is largely pricing detail rather than deeper behavioral traits. Solid but not exceptional beyond annotations.

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?

Content is front-loaded with the core action, then usage, then error/cost details. It is somewhat dense with pricing and billing minutiae, but every sentence contributes relevant invocation context. Slightly verbose rather than wasteful.

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, yet the description explains exactly what is returned (number and conditional address), covers error behavior, and routes to alternatives. Nothing an agent needs to call it correctly is missing.

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?

With 100% schema coverage the baseline is 3, but the description adds real value: it clarifies that a slot can be a decimal index or a 0x 32-byte key, explicit mention of mapping and proxy slots, and a concrete example address. This meaningfully enriches parameter use beyond the schema text.

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 ('Read one raw storage slot of a contract on Sonic'), names the underlying call (eth_getStorageAt), and describes the return shape (32-byte word as number and, when applicable, address). It clearly distinguishes itself from the sibling sonic_proxy.

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?

Explicitly says when to use ('inspect contract state that has no getter, owners or implementation pointers') and redirects to the alternative ('for proxies use sonic_proxy'). The routing condition is unambiguous.

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