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

Annotations already cover safety (readOnly, idempotent, non-destructive), and the description adds real beyond-schema context: no network calls, that EVM addresses get a checksum fix, that Solana on-curve wallets are distinguished from PDAs, and that failures return isError without being charged. That pricing/error-billing disclosure is not derivable from any structured field.

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 the core question, then chains, then guarantees, then cost/error semantics. Dense but every clause carries information; the separate 'Price' and 'Errors' fragments add slight sprawl but are justified.

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?

An output schema exists, so return values need not be explained. For a single-param validator, the description covers supported chains, the no-network guarantee, and error/charge behavior — everything an agent needs to select and call it correctly.

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?

Only one parameter and schema description coverage is 100%, so the schema already documents it fully. The description's chain list adds minor framing but no new meaning about the 'address' string beyond what the schema description says.

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?

Names a specific verb+resource (validate an address) and enumerates exactly which chain formats are handled (EVM, Solana on-curve vs PDA, Bitcoin legacy/P2SH/SegWit/Taproot, Tron, Cosmos bech32). This cleanly differentiates it from siblings like evm_address, ens_resolve, and counterparty_check.

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?

States a clear use context ('catches the typo that would send funds to nowhere') and scopes itself as 'pure checksum and format validation, no network calls', which implicitly routes the agent away from network-dependent siblings. It does not, however, name an alternative tool or state an explicit when-not-to-use condition.

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