Authorise a DRAFT invoice and email it to the contact via Xero. Two-step: sets status to AUTHORISED then triggers email.
| Name | Required | Description | Default |
|---|---|---|---|
| invoice_id | Yes | Xero InvoiceID to authorise and send | |
| api_key_hash | Yes | Customer API key hash identifying Xero token |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses the two-step behavioral trait (AUTHORISED status then email) and the target system (Xero). It does not mention reversibility or error handling, but the core side effects are transparently stated.
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 sentences are front-loaded with the primary purpose, followed by the two-step clarification. Every word earns its place; no filler or redundancy.
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 a mutation with no annotations and no output schema, so more detail is needed. The description explains the operation flow but omits prerequisites (e.g., invoice must be in draft state), failure scenarios, and return values. It is adequate but not complete.
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 no new parameter meaning beyond the schema's descriptions; it merely repeats the context. The schema already explains invoice_id and api_key_hash accurately.
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 authorises a DRAFT invoice and emails it via Xero, with a specific two-step process. This distinguishes it from siblings like draft_invoice and reconcile_transactions by naming the exact verb and resource.
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 implies usage context ('DRAFT invoice', 'authorise and email') and gives a clear trigger condition, but does not explicitly name alternatives or when not to use the tool. It is sufficient for basic selection but 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.
Each tool has a clearly distinct purpose, with complementary pairs like categorise_expenses (suggest) and apply_categories (apply), reconcile_transactions (match) and confirm_reconciliation (apply). No two tools appear to do the same thing.
Most tools follow a consistent verb_noun pattern (e.g., calculate_vat, draft_invoice, send_invoice), but 'health' deviates by being a plain noun, and there is a minor British/American spelling variation ('categorise' vs 'calculate').
9 tools is well-scoped for an accounting MCP, covering VAT calculation, categorization, reconciliation, invoicing, reporting, and health checks without redundancy or bloat.
Core workflows are well-covered, especially the propose/apply pairs for categorization and reconciliation. Minor gaps include lack of invoice read/update actions and no explicit transaction listing, but these are not critical given the server's focus.