PayPing: send invoice

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

Annotations already declare destructiveHint=true and openWorldHint=true, so the agent knows this has real-world, irreversible effects. The description adds the crucial detail that a human recipient is affected and user confirmation is needed, which is context annotations cannot express. It stops short of stating delivery failure behavior or rate limits.

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?

Two short sentences, front-loaded with the action and outcome, then the confirmation warning. No wasted words.

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 output schema covers return values and annotations cover safety, and the description supplies the human-impact warning. However, the sole required parameter is completely undocumented anywhere, which is a significant gap for a tool the agent must invoke 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?

One parameter ('code') with 0% schema description coverage and no explanation in the description. The agent cannot tell whether this is an invoice ID, a customer code, or something else, which is a real gap for a required identifier.

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+resource: sending an invoice to its customer via SMS/email from PayPing. This distinguishes it from read siblings (get_invoice, list_invoices) and from create_invoice, but does not explicitly name those alternatives.

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?

Adds an explicit safety condition: the message reaches a real person, so the agent should confirm with the user first. It does not name a sibling as an alternative, but the when-to-use framing is concrete.

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