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

Annotations already declare readOnly/non-destructive/closed-world, so no safety burden remains; the description instead adds genuine domain context: the enumerated checks, the support caveats (expressions, effects, blend modes patchy on native/mobile players) and concrete thresholds (≈100 KB / 500 KB, >60 fps wasted, >30 fps rarely needed). It does not say anything about the shape or severity model of the findings, which is the remaining gap.

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 correctly: purpose first, invocation second, scope of checks third, exclusion last. The check enumeration is a long run-on whose parenthetical justifications add real information, though it would read better as a structured list.

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?

No output schema exists, so the description carries the full burden of describing results — it implies findings per check but never states the return shape (issue list? per-check pass/fail? severity levels?). For a lint tool whose entire value is the report, that omission is the main completeness gap; input-side completeness is otherwise good.

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% and there is only one parameter, so the baseline is 3; the description goes one step further by clarifying that `json` is the file's *text content*, not a path or URL, which is the one ambiguity an agent could plausibly get wrong.

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 ('Lint a Lottie (Bodymovin) animation') and then enumerates exactly what the lint covers. It is clearly distinct from neighbouring siblings such as check_motion, audit_motion_css or review_animation_principles, which address different artefacts.

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?

Gives an explicit input contract ('Pass `json` as the text of the .json file') and a clear exclusion ('dotLottie (.lottie zip) files are not supported; unzip first'), which prevents a whole class of misinvocation. It stops short of naming a sibling alternative for the unsupported case or for CSS-based motion audits.

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