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

With no annotations, the description carries the full disclosure burden, and it does add real context: the tool is free, pricing is uniform across wallets, and no enrolment or call-history state affects it. However, it omits whether the data is static or refreshed, what currency/units are guaranteed beyond the field name, and whether calling it has any side effects or account requirements beyond the pricing claims.

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 price lead is front-loaded and the whole thing is only three sentences, but the phrasing is promotional and dense ('The exact price every paid signal charges today ... next to its list price'), and the closing sentence restates the free/equal-pricing point already implied by '$0.00 — Free.' Tightening would improve it.

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 zero-parameter, no-annotation, no-output-schema tool, the description covers what matters: it is free, the returned fields (charged price, list price, promotion, end date), and the absence of tiers or enrolment. Given the trivial schema and sibling set, little else is needed to invoke 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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline for an empty schema is 4. Mentioning charged_price_usd and list price names return fields rather than parameters, which is mildly useful but not required here.

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 conveys that this returns pricing data — charged_price_usd versus list price plus any active promotion and its end date — but it never states a verb or explicitly says 'returns the price of every paid signal tool.' The opening '$0.00 — Free' reads as marketing copy rather than a statement of purpose, so the agent must infer that this is a static price-listing endpoint rather than a live quote or a purchase action.

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?

There is no guidance on when to call this versus any sibling, no mention of whether it should be called before subscribing/upgrading, and no exclusions. The 'no tiers, no enrolment, no call-history discount' clause describes the pricing model, not when to use the tool, so it does not function as usage guidance.

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