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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuine context beyond that: the data is scoped to a 30-day window and covers the user's Instagram plus their Facebook page, which tells the agent the breadth and platform limits of the read.

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?

Two sentences, no filler. The first front-loads the returned data and the second front-loads the intended use case, so an agent gets purpose and applicability immediately.

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 input parameters and no output schema, the description must carry the load, and it does list the returned breakdowns and the platform/time scope. The remaining gap is that it doesn't clarify the boundary against sibling analytics tools that may return similar metrics.

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?

The tool takes zero parameters, so per the rubric the baseline is 4. The description correctly adds no parameter detail because there is nothing to parameterize, and it implies the account/platform scope is fixed rather than configurable.

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 names a specific resource (audience demographics) and enumerates exactly what it returns: age, gender, city breakdowns, 30-day totals, and best posting slots. It is clear what the tool does, but it never distinguishes itself from adjacent siblings such as get_follower_stats, get_analytics_overview, get_content_insights, or get_best_posting_times, which plausibly return overlapping data.

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?

It gives two concrete use cases ('who is my audience', grounding a post idea in a real group), which is clear when-to-use guidance. It stops short of when-not-to-use or naming an alternative tool for related questions, so it falls below the top of the scale.

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