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

Annotations already declare readOnlyHint and idempotentHint, so no contradiction exists. The description adds useful context about the data source (Common Crawl) and expected outputs, but does not disclose potential latency, why async might be needed, or error handling behavior. With annotations covering the read-only and idempotency aspects, this is adequate but not rich.

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 concise, with three front-loaded sentences covering purpose, audience, inputs, and outputs. The appended keyword list is slightly redundant but not harmful. It is well-structured and within a reasonable length.

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?

For a moderately complex tool with an output schema, the description covers purpose, data source, inputs, and outputs. It lacks guidance on when to use the async parameter, but that is documented in the schema. Overall it gives enough context to select and begin using the tool without major gaps.

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 description coverage is 75%, and the schema already documents threshold, async, date_range, and affiliate_network. The description restates that inputs are 'affiliate network name and date range' but adds no additional meaning for threshold or async. It meets the baseline but does not compensate for the remaining 25% gap.

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 uses a specific verb ('Analyzes') plus a specific resource ('affiliate clickstream data from Common Crawl') and a clear purpose ('flag potential fraud patterns'). It lists concrete patterns (duplicate IPs, rapid clicks, device spoofing) and distinguishes itself from generic siblings like fraud_detector or x402_payment_fraud_detector by specifying the affiliate domain and data source.

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 clearly establishes when to use it: for CMOs to validate affiliate traffic quality and prevent budget waste. This provides strong contextual guidance. However, it does not explicitly name exclusions or alternatives, so it stops short of a 5.

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