Fetch the signed fairness certificate for a finished deal (state CERTIFIED). Includes the labelled signature (es256 or ed25519) and transparency-log inclusion proof. Verify it with verify_certificate.
| Name | Required | Description | Default |
|---|---|---|---|
| deal_id | Yes | The deal id (d_...). | |
| credential | Yes | Your API key (initiator) or any party's invite token for this deal. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the behavioral burden. It clearly indicates a read operation ('Fetch'), specifies the required state precondition, and describes the returned contents (signature and proof). It does not mention error conditions or side effects, but 'Fetch' strongly implies non-mutating behavior.
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 main action, and includes relevant details (certificate contents, verification pointer) without any unnecessary fluff. Every word adds value.
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 tool is simple (2 params, fully described in schema), and the description covers the output contents and precondition. It lacks details about error cases or authentication specifics, but for a straightforward fetch operation, the context is sufficient.
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 input schema already has 100% coverage for both parameters ('deal_id' and 'credential'). The description does not add extra context about parameter usage beyond what the schema provides, so the baseline of 3 is appropriate for high schema coverage.
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 uses a specific verb ('Fetch') and clearly identifies the resource ('signed fairness certificate') with a condition ('for a finished deal (state CERTIFIED)'). It distinguishes itself from the sibling tool 'verify_certificate' by mentioning that verification is done separately, making the purpose unambiguous.
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 states when to use the tool (for deals in state CERTIFIED) and points to an alternative for verification ('Verify it with verify_certificate'). This gives clear context, though it does not explicitly mention when not to use other deal-related tools.
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.
Each tool has a clear, distinct role in the deal lifecycle: key creation, deal creation, algorithm listing, input validation, commitment computation, committing, revealing, entropy retrieval, certificate fetching, and certificate verification. No two tools appear to do the same thing.
All tool names follow a consistent verb_noun snake_case pattern (e.g., create_deal, get_certificate, verify_certificate). The verbs and nouns are descriptive and match the tool's function. There is no mixing of conventions.
With 11 tools, the set is well-scoped for the fairness deal domain. Each tool earns its place, covering onboarding, deal creation, input handling, execution, and verification without unnecessary redundancy.
The core lifecycle is covered: create key, create deal, inspect algorithms, validate inputs, compute commitments, commit, reveal, fetch entropy for random deals, retrieve certificates, and verify them. The main gap is a tool for counterparties to accept/join a deal using the invite token, but this may be handled outside the MCP server.