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

Annotations already cover read-only/idempotent/closed-world, but the description adds genuinely new behavior: no variable expansion or execution (a real semantic decision an agent must know), determinism, and explicit limits (64 KB input, 1 s per call, 1 MB result). This is substantive disclosure beyond the structured fields.

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?

The opening sentence is well front-loaded, but the entire block is duplicated verbatim in Spanish and English, doubling length without adding information, and the generic 'Cuando: ... datos estructurados (JSON, CSV, YAML, XML, arreglos)' sentence is pure filler for a dotenv parser.

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-shape explanation is rightly omitted, and side-effect/determinism coverage is good. But for a simple parse tool the description spends its words on unrelated format boilerplate and states limits that disagree with the schema, leaving the agent with a plausible but incorrect picture of acceptable input size.

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% for the single `text` parameter, so the baseline is 3, but the description actively introduces a conflicting constraint: it says 'JSON input up to 64 KB' while the schema declares maxLength 1048576 (1 MB). An agent sizing its input gets contradictory guidance, which is worse than silence.

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?

The first sentence states a specific verb and resource (parse .env text into an object) and enumerates supported syntax (KEY=value, export, quotes, escapes, comments) plus the key semantic (no variable expansion). It is distinguishable from yaml-parse. The score is held down by the 'When' clause, which talks about transforming JSON/CSV/YAML/XML/arrays — formats this tool does not handle — muddying an otherwise precise statement.

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?

It names a sibling to avoid (yaml-parse) and says 'no variable expansion', which is a real usage boundary. However the positive 'When' condition is boilerplate about structured data formats (JSON, CSV, YAML, XML) that has nothing to do with dotenv input, so the actual trigger for choosing this tool is left implicit.

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