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

Annotations already establish readOnly/destructive=false, but the description adds material facts they cannot carry: the pricing model ($0.01/call via x402 USDC or card key, first 25 free), that failed calls are free, that repeated calls are charged because the tool is non-idempotent in billing terms, and that a malformed address/slot yields a 400 without charge. It also states the return shape (32-byte word as number, and as an address when applicable).

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 operation and return shape, then usage routing, then error/pricing facts. Dense but nearly every sentence carries new information; the pricing detail is slightly verbose for a tool description but justified by its billing accuracy requirement.

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, and the description compensates by describing exactly what is returned and when an address interpretation applies. Combined with the error and billing behavior, an agent has everything needed to call it correctly and interpret 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 coverage is 100%, so the baseline is 3, but the description adds meaning beyond the schema: it clarifies why a 0x 32-byte key is used ("mapping and proxy slots") and supplies a concrete example address. The slot-format wording largely duplicates the schema, so it stops short of a 5.

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 Berachain") and ties it to the underlying RPC method (eth_getStorageAt). It also names the sibling it must not be confused with (bera_proxy), so an agent can discriminate it from the ~200 other tools without opening a 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?

Explicitly says when to use it ("inspect contract state that has no getter, owners or implementation pointers") and routes proxy work to the alternative ("for proxies use bera_proxy"). It even covers the failure path (400 on malformed input, uncharged), leaving little to inference.

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