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

Annotations already cover readOnly, idempotent, non-destructive, and closed-world, but the description adds genuinely new behavioral facts: zero input, no network request, no payment, and that every result is stamped with an 'unverified claim' label. The provenance/caveat disclosure about results is valuable context the annotations cannot convey.

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?

It is front-loaded with the most decision-relevant fact ('Free.') and then lists return contents in a single dense, waste-free sentence. Every clause earns its place and nothing is redundant.

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?

With no parameters, no output schema, and annotations covering the safety profile, the description carries the remaining burden well by enumerating what the result contains and the caveat label it carries. An agent has everything needed to call 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?

There are zero parameters, so the baseline is 4. The description reinforces this with 'No input', which fully aligns with the empty schema and leaves nothing ambiguous.

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 gives a specific verb ('Return') and enumerates the resources returned: prices of paid tools, payment network (Base), address, licensed data sources, and the 'unverified claim' label. This is far more specific than a tautology. It does not explicitly name or route against any sibling tool, so it stops at 4.

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?

It conveys the usage context — this is the free, no-cost query requiring no input and no network request — which implies when an agent should reach for it (cost/pricing and source-provenance questions). However, it never names an alternative tool or an explicit when-not condition, so guidance is only implied.

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