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

Annotations already declare readOnly, idempotent, openWorld=false and non-destructive, but the description adds determinism, absence of network/stored state, and concrete limits (1 s per call, 1 MB result). One inconsistency holds it below 5: it states a 64 KB input limit while the schema's csv field allows maxLength 1048576, leaving the agent unsure which ceiling actually applies.

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 core operation, then when/not-for, then side effects and limits – a sensible order. It loses a point for duplication: the bilingual ES/EN blocks restate the same content, and the EN section even ends with a self-referential pointer to inputSchema.description.

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 values need no explanation, and the description still covers operation, exclusions, purity, determinism and resource limits. For a 4-parameter read-only parser, nothing an agent needs in order to call it correctly is missing.

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 3 is the floor, and the description earns more by explaining the header-row/array-of-strings branch (which maps to header=false) and that inference covers numbers and booleans plus empty→null. It does not cover the delimiter enum values, but the schema already enumerates them explicitly.

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 and resource: parses RFC 4180 CSV into an array of objects using the header row (or arrays of strings), with optional type inference and a chosen delimiter. The Spanish and EN blocks both name the inverse operation sibling csv-build, so the agent can distinguish them without opening a 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?

Explicit 'Cuándo' clause scopes it to transforming/comparing/checking structured data exactly, and 'No para: convertir un arreglo de objetos en CSV (csv-build)' names the alternative and the condition that selects it. Both the positive trigger and the exclusion are stated.

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