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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is clear without the description. The text adds the meaningful behavioral detail that ranking is based on 'cheapest paid plan' (not free tier), which materially affects results, but says nothing about what the ranked output contains or how ties/missing prices are handled.

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 short sentences with the primary purpose front-loaded and the special case second. Every clause carries information; nothing is padding.

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 an agent gets back — presumably a ranked list of tools with prices — but that is left implicit, as is the meaning of `limit`. It is adequate for a simple read-only ranking tool but leaves real gaps for a three-parameter tool.

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 only 33%: the `by` enum is fully described in-schema, and the description merely restates the cost_per_clip-for-video rule already present there. The `category` enum and especially `limit` (max 20, no stated default or effect on ordering) get no explanation in either place, so the description does not compensate for the low coverage.

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?

The description names a specific verb ('rank') and resource ('AI tools in a category') plus the ranking basis ('cheapest paid plan'), so the agent knows exactly what this produces. It does not differentiate itself from siblings like list_tools or get_prices, which keeps it below a 5.

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?

It implies the use case — you want a cost-ordered view rather than a plain listing — and flags a conditional mode for video ('can rank by cost per clip instead'). There is no explicit when-not guidance and no named alternative for agents who want raw prices (get_prices) or side-by-side comparison (compare_tools).

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