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

Annotations only declare readOnly and openWorld, so the description adds real behavioral value: featured-only mode is restricted to default order with no category filtering, and summaries/media may be incomplete in returned posts. These caveats are not recoverable from the annotations and directly affect how the agent interprets results.

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 first sentence gives the core capability, second paragraph handles exclusions and caveats. Every sentence carries routing or constraint information with no filler.

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 annotations covering read-only safety, a full output schema covering return shape, and 100% schema description coverage, the only remaining burden is routing and caveats, both of which the description supplies. Nothing needed to call this 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% and the property descriptions already explain forum_name format, sort_type enum behavior, page_token continuation semantics, and the featured_only/default coupling. The description largely restates these constraints, so the 3 baseline for high schema coverage 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?

States a specific verb and resource: browse ordinary and pinned posts by exact forum name, without keywords, with pagination and sorting. It also names two siblings and the exact boundary that separates them (keyword search vs. forum detail), so the agent can disambiguate without opening schemas.

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?

Explicitly routes the agent: keyword-based in-forum lookup goes to baidu_tieba_search_posts_in_forum, and forum bio/statistics goes to baidu_tieba_get_forum_detail. It also gives a local usage rule (featured-only supports default order only, no category option), which is exactly the kind of when-to-use guidance that prevents wrong calls.

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