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

There are no annotations, so the description carries the full behavioral burden. It discloses that no API key or account is required, states the cost and payment mechanism, and specifies the return shape as hex and integer. It does not cover rate limits or failure behavior, which keeps it short of a 5 for a no-annotation tool.

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 description is front-loaded with the primary use condition, then alternatives, then operational details. Every sentence contributes: usage, exclusions, return format, auth, and cost. There is no filler.

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?

For a simple three-parameter read tool with no output schema and no annotations, the description supplies the missing context an agent needs: purpose, alternatives, return shape, auth requirements, and cost. Nothing essential is omitted for correct tool selection and invocation.

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 schema already documents address, chain, and slot syntax. The description adds meaningful interpretation of the slot parameter by naming concrete use cases: proxy implementation address, owner, and paused flag. That extra semantic context is useful, though the schema still does the primary parameter documentation.

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?

The description names a specific operation and resource: reading a raw contract storage slot, returned as hex and as an integer. It explicitly distinguishes this from evm_call and evm_token_info, so an agent can tell when this tool is the right one without opening sibling 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?

It gives explicit use conditions ('when an agent must read something a contract does not expose with a getter') and explicit exclusions ('Do not use when the contract has a public getter' or 'for token data'), naming the alternative endpoints to use instead. The routing logic is clear and actionable.

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