evm_fetch_source

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

No annotations are provided, so the description carries the behavioral transparency burden. It does convey that this is a read-only fetch from block explorers and that the source must be verified, which is minimally viable. However, it does not describe failure behavior, return format, or external dependencies like API rate limits.

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?

A single, front-loaded sentence that immediately states the operation and scope. Every word earns its place, and there is no padding or repetition.

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 two-parameter read operation, the description is largely complete: it names the resource, the chain family, and the source of data. Minor gaps remain because there is no output schema and no mention of BSC, but the schema covers the chain enum and the operation is straightforward.

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%, so the input schema already documents both parameters and the chain enum. The description adds no additional parameter-level meaning and even omits BSC from the chain list, though the schema includes it.

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?

Description uses a specific verb ('Fetch') and a specific resource ('verified smart contract source code'), and names the supported chains. It also clearly distinguishes the tool from sibling tools that estimate gas, audit contracts, or decode calldata.

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?

The description gives no explicit guidance on when to choose this tool over alternatives, nor does it state prerequisites or exclusions. Usage context is only implied by the tool name and the phrase 'verified smart contract source code.'

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