VidLens

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

Strong disclosure given zero annotations: includes latency indicator [~5-20s], explains the analytical method (search result analysis), and documents the conceptual return payload (channel-level stats, top videos, landscape summary). Missing only auth/rate limit details.

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?

Perfectly efficient: three sentences front-loaded with the core action, followed by return value description and usage context. The [~5-20s] timing notation is appended without clutter. Zero waste.

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?

Appropriately complete for moderate complexity (4 flat parameters, no output schema). Compensates for missing output schema by describing returns conceptually. Only gap is failure to document the two schema-undocumented parameters (maxChannels, dryRun).

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?

With only 50% schema coverage (niche and regionCode described; maxChannels and dryRun undocumented), the description fails to compensate. No mention of dryRun's purpose (test mode?) or maxChannels' function (result limiting), leaving critical behavioral parameters unexplained.

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?

Excellent specificity: 'Discover active channels in a niche by analyzing who ranks in YouTube search results' provides a concrete verb (Discover), resource (channels), and method (search ranking analysis). Clearly distinguishes from sibling tools like discoverNicheTrends (trends vs. competitors) and inspectChannel (single channel vs. landscape).

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?

Provides contextual timing ('before entering a niche') and use-case ('competitive reconnaissance'), but lacks explicit contrast with alternatives like discoverNicheTrends or inspectChannel, and omits when-NOT-to-use guidance.

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