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 still adds real value: unsupported characters are reported rather than dropped, and it gives concrete limits (64 KB input, 1 s per call, 1 MB result). The 'o desde ella' phrasing mildly blurs the encode-only behavior, but nothing contradicts the annotations.

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?

Content is front-loaded: purpose first, then when/not-for, side effects, determinism, limits. It is a full bilingual duplicate, so roughly half the text is redundant, but each block is individually tight and no sentence is 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?

An output schema exists, so return format needn't be explained, and limits plus determinism are covered. The one real gap is the mismatch between the described 64 KB input ceiling and the schema's 4096-character maxLength, which an agent could trip over when sizing input.

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 100% and there is only one parameter, so the schema already documents 'text'. The description adds the unsupported-character contract, but its stated 64 KB input limit conflicts with the schema's maxLength of 4096, which is more confusing than clarifying.

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+resource ('Codifica texto en código Morse internacional') plus the exact output convention (letters separated by spaces, words by ' / '). It explicitly names the sibling it is not (morse-decode), 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?

Has an explicit 'Cuándo' clause and a 'No para' exclusion naming morse-decode, which is strong routing guidance. Slightly weakened by 'convertir bytes o texto a esta codificación, o desde ella', which implies bidirectional conversion while the exclusion says decode belongs elsewhere.

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