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

Annotations already declare read-only, idempotent, non-destructive and closed-world, and the description still adds real behavior: only posts with a day of views are counted, under 10 posts it compares nothing and warns, results include group sizes and a luck likelihood, and it instructs the agent to frame findings as correlation not causation. That is disclosure the annotations cannot provide.

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 the user phrasings, then the method, then exclusions and safety framing, so an agent can stop reading early. It is dense and the long enumerated comparison list makes one sentence heavy, but no sentence is 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?

Even though an output schema exists, the description still characterizes the return shape (biggest gaps, group counts, luck likelihood, low-data warning), so an agent knows what it will get. The one remaining gap is that data-source prerequisites (e.g. which platforms need a connected account) are left implicit.

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 0%, so the description has to carry both parameters, and it does: `days` is explained as the lookback window over the user's own posts with a 90-day default, and `timezone` as the IANA zone used for the time-of-day grouping, with an example. This adds meaning well beyond the bare integer/string schema.

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 concrete operation: it compares 24-hour view counts across the user's own posts by clip length, caption length, platform, weekday, time of day and title. That is specific enough to separate it from compare_platforms, whats_taking_off and explain_clips without opening a 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 phrasings ("why did that one do well", "what should I do more of") and an explicit "Not for:" clause naming predicting views, best_time_to_post and weekly_report as the alternatives. When-to-use and when-not-to-use are both covered.

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