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

With no annotations, the description carries the full burden. It clearly states the tool is a read/search operation, filters results by relevance, and has deployment-specific limitations (realtime_unavailable). This goes beyond a bare 'search' and provides useful behavioral context without contradicting any annotations (none exist). It could mention the return format or pagination, but the output schema exists, which reduces the need.

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?

The description is concise at three sentences. It front-loads the core purpose in the first sentence, then adds important behavioral notes. No fluff or redundancy. Each sentence adds value: purpose, data source behavior, and deployment limitation. It could be slightly more structured (e.g., bullet points) but is appropriately sized.

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?

Given the tool's moderate complexity (3 params, all optional, no required params, and an output schema), the description covers essential aspects: what it searches, how it behaves (corpus vs live), and a key limitation. The output schema likely describes the return structure, so the description doesn't need to repeat that. It lacks explicit examples or edge cases, but the description is sufficient for an agent to call it correctly in most cases.

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 schema already documents each parameter (query, subreddit, limit). The description adds minimal parameter-level detail, but it does clarify that search is by 'query and/or subreddit,' implying that either or both can be used, which aligns with all optional parameters. Since the schema is thorough, the description doesn't need to repeat details; a score above baseline is justified for the implicit relationship.

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 clear purpose: 'Search Reddit discussions by query and/or subreddit.' It specifically names the resource (Reddit discussions) and the two dimensions of search (query, subreddit). However, it doesn't explicitly differentiate from siblings like search_x or search_producthunt, though the resource is implied by the name and query structure.

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 description explains that the tool prefers a local corpus and may supplement with live fetch when configured, giving context on data source behavior. It also warns that on some deployments only the corpus path is available (realtime_unavailable), which helps agents set expectations. However, it doesn't explicitly state when to use this vs a specific sibling (e.g., search_x for Twitter), so guidance is clear but not exhaustive.

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