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

With no annotations, the description carries the full burden. It usefully discloses the default-latest behavior and the network-specific quirk that 'numero' is ignored on Solana, but says nothing about read-only nature, error behavior, or what the returned block data contains.

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?

Very compact and front-loaded, with the key behavior ('último' default) stated in the first line before the argument details. No wasted sentences, though the 'Args:' block is slightly terse.

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?

For a 2-parameter read tool with no output schema and no annotations, the description covers the parameters and the default behavior adequately. It leaves gaps around return value contents and error cases, which an agent would need when interpreting results.

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 0%, so the description must compensate, and it does: it enumerates the valid 'red' values (base, ethereum, solana) and explains 'numero' as a block number that only applies to EVM chains. This adds real meaning the bare schema lacks, though it doesn't clarify the default empty-string semantics of 'numero'.

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 resource (block data) with a clear default behavior when the block number is omitted. It is distinguishable from siblings like transaccion or estado by resource, but never names or contrasts with any sibling explicitly, 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?

The phrase 'sin número, el último' tells the agent what happens when 'numero' is omitted, which is useful usage context. However, there is no guidance on when to prefer this tool over siblings such as transaccion or estado, so usage is only implied.

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