library_search

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

With no annotations supplied, the description carries the full burden and delivers unusual detail: per-panel/per-subcategory result caps (最多 300 条), a fully specified ranking order (exact title > prefix > contains > category match > rest), the meaning of the matched field, a 10-minute result cache that makes paging free, and the lifetime of returned *_ref handles (valid for this MCP run). This is exactly the operational context an agent cannot infer from the schema.

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?

Purpose and matching behavior are front-loaded, then ranking, pagination, and return fields follow in a logical order. It is dense but long, and the kind enum listing and cap repetition add bulk that could be tightened without losing information.

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 7-parameter search tool with no annotations and no output schema, the description still documents the return shape (template_id, title, panel_key, kind, cover_ref, total, by_panel, matched_categories, related_categories), the full kind enumeration, and how to consume *_ref values via image_view. Nothing an agent needs in order to call it correctly is missing.

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%, so the baseline is 3, but the description adds real meaning: it links queries to synonym-batch usage with a concrete example, ties offset/count to the cache so paging does not re-request, and connects panel_key to the by_panel return field for narrowing. It does not clarify the instance_id/project_path either-or beyond what the schema already says.

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 states a specific verb+resource (按关键词搜索官方素材库) and enumerates the covered domains (美妆、滤镜、贴纸、音效等), so an agent can immediately tell this is the keyword-search path over the material library. It also names the sibling boundary — library_list for enumerating categories, image_view for resolving refs — which most search tools omit.

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 gives concrete usage context: semantic/panel-name matching with worked examples (「滤镜」→滤镜面板, 「腮红」→美妆/腮红), queries for up to 8 synonyms, and panel_key to narrow from by_panel. It does not explicitly state when to prefer library_list or library_images over searching, but the routing to library_list for related_categories implies the boundary.

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