Vanity address estimate

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

The readOnlyHint=true annotation already establishes this is a safe, non-destructive operation. The description adds that it is a pure estimation/computation returning difficulty, attempts, time, and optionally a CREATE2 address. Beyond that it discloses nothing further (no rate limits, precision caveats), which is acceptable given it is a stateless calculation 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?

Two tight sentences with no waste, front-loading the primary estimation purpose before the secondary CREATE2 capability. Efficient and well-ordered, though the CREATE2 sentence is somewhat dense for a secondary feature.

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?

With no output schema, the description appropriately names what is returned (difficulty, expected attempts, time, CREATE2 address). It covers both input modes and the read-only profile, leaving only output formatting/units and CREATE2 result details unspecified.

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 0%, so the description must carry the load, and it largely does: 'prefix', the case-insensitive/EIP-55 toggle (mapping to caseSensitive), 'keys/s rate' (keysPerSecond), and all three create2 fields (deployer, salt, initCode) are named conceptually. It does not give value formats (0x address, salt/initCode encoding) or clarify that create2 is a nested object, leaving some gaps.

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+resource: computing difficulty and expected attempts for an Ethereum vanity prefix, plus time at a keys/s rate. It even distinguishes the two prefix-matching modes (case-insensitive vs EIP-55) and declares a secondary CREATE2 computation. An agent immediately knows what this does, and no sibling tool overlaps this function.

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 implies the two usage modes (provide a prefix, or provide deployer+salt+initCode for CREATE2), which is enough context to select the right inputs. But it never states when to prefer this versus alternatives, nor any prerequisites or exclusions. Usage is inferred rather than instructed.

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