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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuine behavioral context via 'Featured tools are ranked first', which tells the agent result ordering is not purely relevance-based; however it says nothing about result shape, empty-result behavior, or whether limit truncates silently.

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 tight sentences, zero filler. The verb+resource identification comes first and the ranking caveat follows, so the most decision-relevant information is front-loaded.

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 simple four-parameter read-only search with full schema coverage and annotations, the description covers domain scope, filter facets, bilingual matching, and result ordering. The only remaining gap is return-value shape (no output schema), which is a minor omission rather than a blocker.

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 all four parameters (query, category, pricing, limit) are already documented with examples. The description restates the filter axes without adding format, matching, or combination semantics beyond what the schema provides, so baseline 3 applies.

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?

Names a specific verb and resource ('Search the LingYi Tools AI directory') and enumerates the three filter axes (keyword, category, pricing). It is distinguishable from get_tool/list_categories/list_featured by being a multi-facet search, though it never names those siblings explicitly.

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?

The available filter axes imply when to reach for this tool, but there is no explicit when-to-use/when-not guidance and no routing to alternatives such as list_featured or get_tool when the agent already has an id.

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