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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, yet the description still adds real behavior: the output is deliberately unfinished scaffolding that must be rewritten, and it depends on upstream trend data. No contradiction with annotations. Auth/uid and durable-state behavior are left to the schema.

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?

Three dense sentences with no filler: purpose first, then the scaffolding warning, then the trend_context pointer. Each sentence changes how an agent would call or present the tool.

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 13 optional parameters and no output schema, the description compensates by describing the exact shape of each returned idea and the state of the output (scaffolding, not final). Nothing an agent needs in order to call and correctly present results is missing.

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 92%, so the baseline is 3; the description adds genuine meaning by explaining how brand/product/audience/pain_points are combined and by specifying that trend_context is the summary object returned by find_viral_trends, which the schema only hints at. The remaining 13 parameters (uid, bearer_token, preferences_mode, conversation_id) are covered by the schema, not the prose.

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 and resource ('Generate structured UGC video ideas') and explains the mechanism: crossing a named library of short-form formats with brand/product/audience/pain points. It also enumerates the output's anatomy (hook, 3-beat outline, why it works, CTA), which separates it from downstream siblings like draft_ugc_script that produce finished copy.

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 two concrete usage rules: pass trend_context from find_viral_trends for trend-aware ideas, and rewrite the scaffolding before presenting. That names an upstream sibling and its condition. It stops short of an explicit when-not-to-use or a named handoff to draft_ugc_script for the rewriting step.

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