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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: the per-call cost, payment methods, the fact that an unpaid call returns an offer with x402 PaymentRequired, and that invalid input is refused before payment. It also discloses that TVR's non-public score transformation is applied, which is a meaningful behavioral trait.

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 dense but well-structured, front-loading the most important fact ('Paid') and then covering payment, alternatives, and data source in a compact paragraph. Every sentence earns its place, though it could be slightly more scannable with line breaks or bullet points.

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 description is complete for a paid, read-only tool with an output schema. It covers cost, payment methods, failure behavior, free alternatives, and data source. The output schema exists, so return values need not be explained in the description. Nothing an agent needs to call this tool correctly 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 description coverage is 100%, so the schema already documents both parameters thoroughly. The description adds context about the weights ('your own weights for the 8 fundamental metrics') and the output fields, but it doesn't add much beyond the schema's detailed parameter descriptions. Baseline 3 is appropriate since the schema does the heavy lifting.

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 ('Reranks'), a resource ('every coin TVR covers'), and the mechanism ('your own weights for the 8 fundamental metrics'). It also names the output fields (rank, TVR Score, valuation category, fair value gap, TVR Estimated Value), which makes the tool's purpose unmistakable and distinguishes it from siblings like get_top_ranked and get_tvr_score.

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 explicitly says this is a paid tool, names the free alternative ('get_top_ranked and the four presets'), and explains the payment flow (unpaid call returns the offer, charges nothing). It also states that invalid input is refused before payment, giving an agent clear conditions for when to use this tool versus alternatives.

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