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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds real behavioral value beyond that: the Empire-plan gating and the fallback behavior (returns an upgrade message on other plans), which an agent needs to interpret a non-data response.

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 purpose and scope, and the plan caveat is placed last. It is a single dense sentence plus a short caveat, efficient overall, though the content enumeration is somewhat packed.

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 carries the burden of explaining what is returned, and it does so explicitly (trend lines, bottlenecks, best formats, platforms with data). Combined with the plan-gating note, an agent has everything needed to call and interpret this tool.

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%, with the enum values (7/30/90) and default 30 already documented in the schema. The description repeats the valid windows but adds no new format or semantics beyond what the schema provides, so baseline 3 applies.

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+resource (get the Growth Hub overview) and enumerates the exact content returned: per-platform engagement trend lines, weakest platforms, best-performing formats, and platforms with real trend data. This content profile cleanly separates it from siblings like get_analytics_trends and get_stats, which cover different scopes.

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 a clear prerequisite (requires the Empire plan; otherwise returns an upgrade message), which is genuinely useful context. However, it never says when to choose this over get_analytics_trends, get_optimization_insights, or get_trend_performance, so alternative selection is left to inference.

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