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

Annotations already cover the read-only and open-world profile, and the description adds scope constraints beyond them: no pagination (so the agent should not attempt page/offset arguments) and no hot-video payloads. It does not discuss freshness, region, or rate limits, but for a zero-parameter read that is a minor 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?

A single front-loaded sentence with a semicolon-delimited scope exclusion; every clause carries information and nothing is redundant. The positive capability is stated before the limitations, which is the right ordering.

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?

For a zero-parameter read with an output schema already documenting return shape, the description covers what is fetched and what is explicitly out of scope. Only secondary operational context such as data freshness or regional scoping is absent, which is minor at this complexity.

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?

The tool takes no parameters, so the baseline is 4; there is nothing for the description to clarify beyond the useful note that pagination is unsupported. The schema already enforces additionalProperties=false with an empty property set.

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 and resource — retrieves Haokan Video's current search hot words together with their heat values — and preempts the most likely confusion by declaring it does not return hot video lists. An agent can distinguish it from haokan_search_videos and haokan_search_suggestions without opening any 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?

Usage is implied by the resource description (call it when trending search terms are needed), and the negative clause hints that a different tool covers hot videos. However, no sibling is named as an alternative and no explicit when-not condition is given, so the routing is left partly to inference.

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