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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), but the description adds real behavioral detail beyond them: the return is text in the selected format, and the operation is lossy in specific ways (trims strings, deduplicates rows, may drop mostly empty columns). The 'may drop' wording is honest disclosure of a data-dropping side effect.

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?

Two tight sentences: purpose first, then usage routing plus a behavioral summary. No filler, no repetition of the name or title, and the alternative tool is named in the same breath as the constraint.

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?

With no output schema, the description correctly covers the return ('text in the selected format') and the transformations applied, which is what an agent needs for a 2-parameter tool. Minor gap: it does not note the 4096-character input ceiling or any failure behavior, though the length cap is already in the schema.

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 100%, so both 'input' and 'format' (including the auto/json/jsonl/csv enum) are already documented in the schema. The description's mention of 'the selected format' and the three formats echoes the schema without adding syntax or format-specific semantics, so baseline 3 applies.

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 concrete verb pair (clean and compact) plus the exact resource (JSON, JSONL or CSV rows), and the title/description together make the 'minify structured data' role unmistakable against siblings like minify-css or minify-html. An agent can distinguish it from generate-dataset and is-json-safe without opening the 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?

'Use for small datasets' gives a clear scope condition, and it explicitly routes the agent to is-json-safe for the syntax-check-without-changes case. It stops short of stating what happens on larger inputs or naming other alternatives, so it is strong but not exhaustive.

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