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

With no annotations, the description carries the full burden, and it does disclose one real behavior: the fields are returned only 'si los expone', warning that results may be empty or partial. It says nothing about read-only nature, failure modes for invalid addresses, or supported chains beyond the two named. Useful but thin disclosure for an annotation-free 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?

One front-loaded sentence stating the return payload, followed by a compact Args block. No filler, no restatement of the tool name, and every line earns its place.

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?

There is no output schema and no annotations, so the description must cover everything; it states the returned fields and their conditional presence but omits error behavior for non-contract addresses and how to proceed when fields are absent. Adequate minimum for a 2-param read tool, but with visible gaps.

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 coverage is 0% — the schema offers only bare titles 'Red' and 'Contrato'. The description compensates by enumerating the accepted values for red (`base` o `ethereum`, effectively an enum absent from the schema) and clarifying that contrato is a contract address. That is meaningful added meaning, held back from 5 only because formats are still not fully pinned down.

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 the resource (contrato) and exactly what it returns: símbolo, nombre y decimales. That is more specific than the sibling names like estado or precio, and an agent can tell this is the metadata lookup rather than a balance or price call. It lacks an explicit verb and never names a sibling it differs from, so it stops short of a 5.

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?

There is no when-to-use guidance beyond the implied 'fetch contract metadata'. It never says how this relates to es_contrato (checking whether an address is a contract) or when the two should be chained. The qualifier 'si los expone' hints at a precondition but is not framed as usage advice.

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