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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely new behavioral context: it is not a parser, not AST-aware, is conservative, that behavior should be regression-tested, and that it returns source text rather than a boolean. The 'not a boolean validator' note corrects an expectation created by the is-* naming family.

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 verb and the key caveat, and nearly every sentence carries distinct information. Slightly redundant in stacking three separate negations ('Not a parser', 'not AST-aware', 'not a boolean validator'), but each targets a different misconception.

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?

Although there is no output schema, the description states the return value explicitly ('Returns compacted JavaScript source text'), and it covers input scope, limitations, and safety expectations. An agent has everything needed to call and interpret it correctly.

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?

Only one parameter and schema coverage is 100%, so the schema fully documents 'code' including the 4096-char limit. The description only loosely constrains input ('small JavaScript snippets') and adds no format or syntax guidance beyond the schema, matching the baseline-3 expectation.

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+resource (Conservative JS minification / compacted JavaScript source text) and immediately distinguishes itself from the is-minify-css sibling and from real parser-based minifiers. The phrase 'Transformation tool, not a boolean validator' also disambiguates it from the many is-*-safe predicate siblings.

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 when-to-use ('small JavaScript snippets where basic whitespace cleanup suffices'), explicit when-not ('for safe production bundling use a real JavaScript parser/minifier'), and names the alternative for CSS (is-minify-css). Nothing is left to inference.

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