JSON to types (TypeScript, Go, Python, Zod)

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

Annotations already establish readOnlyHint/openWorldHint=false/idempotentHint=true, so the bar is lower, and the description still pays off richly by disclosing the inference algorithm: all array items merged, missing keys become optional, null yields nullability, int+float collapse to number/float64, mixed values become unions, and identical shapes share a name. That is exactly the kind of behavior an agent cannot get from annotations. One tension: annotations say readOnly, yet the `output` parameter writes a file to disk (the description stays silent on this side effect, so the safety profile is not qualified).

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 purpose, then the useful merging rules, with zero fluff. The one sentence that does not earn its place is "These four are every language the website supports," which tells an invoking agent nothing actionable; the trailing URL is defensible as attribution.

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 should convey what comes back; it effectively does by describing each generated artifact, and the merge semantics cover the tricky cases of a sample-driven generator. The gaps are minor: it does not say the code is returned as text (versus only written to `output`), and it leaves the file-write side effect of `output` unexplained relative to the readOnly annotation.

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 the baseline is 3 and the schema already documents all eight parameters. The description adds meaning for a few of them indirectly — "TypeScript interfaces (or type aliases)" maps to tsTypeAlias, "optional omitempty" maps to goOmitEmpty, and "Give text or a path" restates the input choice — but `export`, `output`, and `rootName` are never touched on, so it does not beat the schema by much.

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?

Opens with a specific verb+resource ("Generate type definitions from a JSON sample") and enumerates the four concrete outputs with their idioms, so the agent knows exactly what it gets back. It does not, however, distinguish itself from the sibling ai_json_schema_infer, which infers a JSON Schema from the same kind of input — the only sibling-differentiating sentence is the meta remark about "every language the website supports," which does not help selection.

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?

Usage is implied rather than stated: you supply a JSON sample and pick a language. The one piece of routing guidance is "Give 'text' or a file 'path'", plus a hint that path suits big inputs. There is no explicit when-to-use/when-not, no mention of ai_json_schema_infer as the alternative when the user actually wants a schema rather than code.

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