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

No annotations are present, so the description carries the full burden of behavioral disclosure. It reveals a price ('$0.09 via x402') and that it is a 'live feed,' but it does not disclose how the live feed behaves (e.g., push vs. poll, response format, rate limits, authentication, or what happens without a paid payload). For a tool with zero annotation support, this is not enough.

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 a single compact sentence with no wasted words. It includes price, payment mechanism, and the live-feed substance. Not perfectly front-loaded because the price comes before the core purpose, but still efficient and readable.

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?

Given the tool has no output schema and no annotations, the description must explain a lot, but it leaves major aspects unspecified: how to invoke the live feed, what the response looks like, how real-time it is, and the exact role of the x_payment payload. The description is too thin to fully guide invocation.

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% and the only parameter, x_payment, is described as 'Optional signed x402 payment payload' in the schema. The description adds no parameter-level semantics beyond that, but with complete schema coverage the baseline of 3 is appropriate.

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-resource: 'live feed of which brands/categories are being checked for AI-search visibility right now.' This clearly communicates what the tool does and is semantically distinct from siblings like brand_ai_visibility_check (a per-brand check) and ai_visibility_index (a static index). It lacks an explicit contrast with siblings, so it stops short of a 5.

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?

No guidance on when to use this tool versus alternatives, no prerequisites, and no mention of what scenarios justify calling it. The description merely describes the feed but implies nothing about selection criteria or conditions like whether a x402 payment is required upfront.

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