Get network payment methods

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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds genuine behavioral context beyond them: this is a public catalog requiring no networking scope, and API keys are refused for non-balance methods.

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?

Three compact sentences with the read-only/no-payment constraint front-loaded, followed by selection guidance and scope notes. No filler, though the phrase 'needs no networking scope' is slightly tangential for a reader deciding whether to call 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 read-only catalog with no output schema and no annotations gap, the description covers when and why to call it, but leaves the sole parameter undocumented and does not describe what fields the returned metadata contains beyond hinting at a system field.

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 is exactly one parameter, country, with 0% schema description coverage and no enum, yet the description never mentions it at all. The agent gets no hint about the two-letter country code format or whether it is required, so the description fails to compensate for the coverage 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?

States a specific verb and resource ('Read payment-method metadata') and immediately scopes it with 'without starting payment', which separates it from the quote/order payment siblings. It is clear what the tool returns, though it never names a nearest alternative tool explicitly.

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?

Gives concrete selection guidance: pick the item whose system=balance for API-key network purchases, and warns that other methods are refused for API keys. That is actionable when-to-use context, but it stops short of naming which sibling to call for non-API-key payments.

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