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

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds behavioral context: it spends credits, reads the saved brand, can switch the active brand via brandId, and gathers data from external sources (Reddit, TikTok, reviews). This adds value beyond annotations without contradiction.

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?

The description is moderately long but densely informative. It front-loads the purpose, then details the output, usage, alternative tool, and cost. Each sentence adds value, and the structure is logical: purpose → output → parameter usage → alternative → cost. It could be slightly more concise, but the detail is warranted given the tool's complexity.

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?

The tool has no output schema, so the description must explain the return format, and it does thoroughly (ranked angle bank with tags, quotes, score breakdown, and hook). It covers what data it reads, the parameter, side effects (brand switching, credit cost), and the competitor alternative. Minor gaps include not addressing behavior when no brand exists or possible delays, but these are not critical for an agent to use it correctly.

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 schema describes brandId as 'a brand id/name from list_brands to mine for; omit to use the active brand' (100% coverage). The description enhances this by explaining that passing brandId switches the key's active brand like use_brand, which is a behavioral nuance not in the schema. This adds meaning beyond the schema description.

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 states a specific verb and resource: 'Mine ad ANGLES from real customer language' and details the output (ranked angle bank with tags, quotes, score, hook). It explicitly distinguishes from sibling 'competitor_teardown' by naming it for competitor use, and references 'use_brand' for brand switching, making the tool's purpose unambiguous.

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?

The description gives clear when-to-use context: for mining angles from customer language, and explicitly says 'To tear down a COMPETITOR use competitor_teardown instead.' It also explains the brandId parameter's effect (switches active brand like use_brand). While it doesn't list all alternatives, the primary exclusion (competitor_teardown) is clear, and the use case is well implied.

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