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

It discloses a lot beyond the annotations: missing property reads return null, RPC failures return 502, EOAs return not-applicable, empty slots do not prove an uninitialized proxy, and ownership renunciation requires a confirmed zero owner. It even resolves the apparent annotation oddity by explaining "not marked read-only because each call is charged," which directly reconciles readOnlyHint=false with a non-mutating operation.

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 capability, then limitations, then usage, pricing, and the read-only caveat. Every sentence carries information, though the final cluster (example, price, credit key, failed-call policy) is dense and slightly crowded for a single description block.

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 supplies the return-value semantics itself (null, 502, not-applicable) plus pricing and auth mechanics (x402 USDC, card key, free tier). Nothing an agent needs to call this correctly or interpret its results is missing.

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% for the single address parameter, so the schema already carries the format contract. The description only adds a concrete example address, which is illustrative rather than adding semantic meaning beyond the schema; baseline 3 applies.

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 opening sentence names the concrete resources analyzed (Base contract bytecode, EIP-1967 proxy slot, zero-supply) and the method (heuristics), which clearly separates it from audit-style siblings like wallet_audit and liquidity_pool_audit. An agent can tell this is a contract-level risk heuristic read without opening the 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?

"Use before approving or calling an unfamiliar Base contract" gives a concrete trigger, and "Not a full security audit; see endpoint details for coverage limits" draws an explicit boundary on when not to rely on it. No alternative sibling is named by name, so it stops short of a 5.

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