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

Annotations already cover safety (readOnlyHint) and scope (openWorldHint), so the bar is lower. The description adds real behavioral context beyond them: it reads the real connected channel directly, needs no input, and explicitly forbids asking the creator for context/links/titles first. It does not disclose output shape or pagination/limits, keeping it below a 5.

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 with purpose, then usage triggers, then the parameter rule, then routing to siblings — a logical order. It is on the long side and mildly repetitive in the closing 'never ask... not for context, not for a link, not for a title' triplet, but every sentence carries routing or behavioral weight.

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 no output schema, the description must convey return content, and it does: themes, audience wants/needs/struggles, unanswered count. Combined with the annotation-provided safety and scope, an agent has what it needs to call this correctly; only the unexplained `title` parameter and any result-size limits are unaddressed.

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 50%: the `video` param is documented in the schema, and the description adds meaning there (title or partial title, one upload vs whole channel). However `title` is undocumented in both schema and description, leaving the agent to guess its role from a sibling name. Baseline 3 applies given the partial coverage gap.

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 (read/summarize) and resource (audience YouTube comments for the user's channel) and enumerates the exact outputs: recurring themes, what the audience wants/struggles with, and count of unanswered comments. It explicitly distinguishes itself from analyze_audience and suggest_ideas, so an agent can route correctly without opening either schema.

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?

Gives explicit trigger conditions ('what their audience wants or struggles with', 'what people are saying'), names the sibling alternatives for adjacent intents, and specifies the video-vs-channel decision rule with concrete example utterances. Near-complete when-to-use coverage.

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