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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered; the description adds genuinely non-structured context: the $0.003 USDC x402 cost and a 'facts, not advice' disclaimer. It does not say what happens when the address is not a token contract, which is the main remaining behavioral gap.

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?

One dense, front-loaded sentence lists the returned fields, followed by two short clauses on read-only status and pricing. Nothing is buried and nothing is redundant, though the 'not advice' clause is marginal 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?

With no output schema, the description carries the burden of describing returns and does so thoroughly by naming each field, including derived plain-language notes. Only error/edge-case behavior for non-contract addresses 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?

There is one required parameter at 100% schema coverage, so the schema already carries the definition. The description adds nothing about input format (address only? symbol accepted?) or validation, leaving it at the baseline for fully-covered schemas.

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 resource (Base token contract facts) and enumerates exactly what is returned: name, symbol, decimals, supply, code size, owner(), and EIP-1967 implementation. That enumeration distinguishes it from siblings like base_erc20_balance and base_price, though it never explicitly contrasts with the closer base_contract.

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?

Usage is implied by the enumerated facts (e.g. checking upgradeability or renounced ownership), but there is no explicit when-to-use statement, no exclusions, and no pointer to base_contract or base_name for overlapping questions. The agent must infer that this is the token-metadata tool.

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