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

Adds real disclosure beyond the annotations: no side effects, no network, no stored state, determinism, and concrete limits (64 KB input, 1 s, 1 MB result). Minor internal noise: saying it converts text 'to or from this encoding' blurs the very decode boundary established later, and the 64 KB input cap reads oddly against the schema's 1 MB maxLength.

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 operation and modes, then tightly labelled sentences for when/not-for/side effects/limits, so an agent can scan it. The full Spanish/English duplication roughly doubles length for no added information, which is the main inefficiency.

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?

Covers everything needed to call it correctly: mode semantics, the decode alternative, safety profile, determinism, and size/time limits. An output schema exists, so return-value explanation is not required, and nothing material is left implicit.

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%, so the baseline is 3, but the description genuinely adds meaning to the mode enum by mapping component/form/path to recognizable encoding standards and behaviours (space as +, '/' preserved). The text parameter is only echoed, not enriched.

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 specific operation (percent-encoding text for a URL) and breaks it into three named modes with concrete semantics (encodeURIComponent-like, space as +, keeps /). It also explicitly names the sibling it is not, url-decode, so an agent can distinguish the pair 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?

'When:' gives the triggering condition (need exact conversion to/from this encoding without guessing) and 'No para:'/'Not for:' names the excluded case plus the alternative tool url-decode. That is explicit when/when-not/alternative guidance.

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