Return the x402 payment challenge needed to top up credits for an existing agent endpoint. Accepts either a dashboard PAT with mcp:endpoints:write or mcp:* or a legacy endpoint API key.
| Name | Required | Description | Default |
|---|---|---|---|
| slug | Yes | Slug of the endpoint to top up | |
| apiKey | No | Legacy endpoint API key (x402_*) | |
| accessToken | No | Your dashboard MCP personal access token (sgl_pat_*) | |
| topupAmount | Yes | USDC amount to add, minimum 1 |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It does mention the authentication requirements and that a challenge is returned, but it does not explicitly state whether this operation is read-only, has side effects, or how the challenge is used afterward. This leaves some ambiguity about the operation's nature, though it is useful context.
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 two sentences, front-loaded with the primary purpose and followed by a concise note on authentication. No redundant or filler content; every phrase adds information.
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?
There is no output schema, and the description does not explain the format of the returned payment challenge or the next steps (e.g., using the challenge with a payment execution tool). Given the tool is about payment, this is a notable gap. The description is sufficient for basic understanding but incomplete for a complex payment flow.
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 coverage is 100%, so the baseline is 3. The description adds value by clarifying the relationship between apiKey and accessToken (either/or selection) and by indicating which slug and topupAmount are for. This goes beyond the schema's field descriptions, particularly for the authentication parameters.
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 clearly states the tool's function: 'Return the x402 payment challenge needed to top up credits for an existing agent endpoint.' This uses a specific verb (return) and resource (payment challenge for topping up), and distinguishes it from siblings like request_endpoint_creation_payment by specifying 'existing agent endpoint.' The auth note further clarifies its scope.
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 provides clear usage context by specifying acceptable authentication methods: a dashboard PAT with mcp:endpoints:write or mcp:* , or a legacy endpoint API key. It also implies this is for existing endpoints, differentiating it from creation-payment tools. However, it does not explicitly name alternative tools or state when not to use this one, so it lacks explicit exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Most tools pair a clear verb with a distinct resource noun, so endpoints, agents, datasets, campaigns, products, and vault operations are generally easy to separate. The main risk is the repeated request_*_payment / *_with_payment pairs and the two create_*_with_payment tools, which are only distinguishable by reading descriptions carefully.
The dominant pattern is verb_noun snake_case, such as list_my_endpoints, update_campaign, and finalize_agent_registration, and the payment/request pairs are consistently named. The vault_* tools use a namespace prefix rather than verb-first names, and vault_how_to_backup breaks the action-oriented convention, so it is not perfectly uniform.
48 tools is a very large MCP surface, well beyond the 25-tool threshold where selection becomes a serious burden. Even though the server spans multiple domains, the count feels excessive for a single agent-facing tool set and should likely be split by domain.
The core endpoint, agent, marketplace, and payment flows are well covered, including creation, updates, stats, and two-phase x402 purchases. However, there is no create_product or delete_product, campaigns lack delete, and there is no way to list previously purchased datasets, leaving notable lifecycle gaps.