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

Annotations already declare readOnly/idempotent/non-destructive/openWorld=false, and the description adds concrete context on top: no network access, no stored state, deterministic output, and hard limits (64 KB JSON input, 1 s per call, 1 MB result). It also scopes the check to syntax and checksum only, which prevents an agent from assuming semantic/on-chain validation.

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 purpose, then labeled sections for conditions, exclusions, side effects and limits, so an agent can skim. It loses a point because the body is duplicated verbatim in the inputSchema description and closes with a dangling pointer ('[EN completo / full EN: inputSchema.description]') that adds no information.

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, annotations cover the safety profile, and the description supplies the remaining operational context: offline nature, determinism, and size/time limits. Nothing an agent needs in order to call this correctly 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?

With one parameter and 100% schema coverage, the schema already documents the field, but the description adds real semantic meaning by defining which address grammars are accepted and that validation stops at syntax plus checksum. It does not restate the maxLength, but the accepted-format detail is more useful than that.

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 and resource (validate a Bitcoin address) and enumerates the exact address families and encodings covered: Base58Check P2PKH/P2SH and Bech32/Bech32m SegWit with BIP-173/350 rules. It also names the sibling it is not (solana-address-validate), so an agent can route without opening either 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?

The 'Cuándo' line gives the triggering condition (offline verification of format and check digit before using an identifier) and the 'No para' line explicitly excludes the Solana public-key case with the alternative tool named. This is the full when/when-not/alternative triad.

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