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

Annotations already establish read-only, non-destructive, open-world and non-idempotent behavior; the description usefully reinforces this ('reads or computes only and changes nothing') and explains WHY repeats are not free (per-call charge, consistent with idempotentHint=false). It adds real context beyond annotations — billing, first-25-free, failed-call refund, and 400-on-malformed-input uncharged — but these are pricing/error details rather than deeper contract-state behavior such as what zero-slot or undeployed addresses return.

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 operation, then return shape, then usage and exclusion, then edge cases. Every clause carries information — even the pricing and 400-rejection notes affect agent decision-making about retries — with no filler sentences.

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 describes the return value (32-byte word as number, address form when it holds one), covers error handling (400 uncharged), cost model, and the free/paid semantics. Nothing material is missing for a two-parameter read 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 coverage is 100%, so baseline is 3; the description goes further by explaining what the slot string actually denotes (decimal index or 0x 32-byte key, used for mapping and proxy slots) and gives a concrete address example. That is meaningfully more than the terse schema blurbs.

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 HyperEVM — and names the underlying RPC method (eth_getStorageAt) plus the exact return shape (32-byte word as number, and as address when applicable). It also distinguishes itself from the sibling hyperevm_proxy, so an agent can separate the two without opening schemas.

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 it (inspect contract state that has no getter, owner slots, implementation pointers) and when not to (for proxies use hyperevm_proxy). The slot parameter guidance — decimal index versus 0x 32-byte key for mapping/proxy slots — further helps an agent decide it has the right inputs.

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