create-invoice

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

No annotations are provided, so the description carries full burden. It discloses that a deep link is returned and should be displayed, which is useful behavioral context. However, it lacks details on permissions needed, error handling, whether the operation is idempotent, or any rate limits—significant gaps for a creation tool with no annotation coverage.

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 appropriately sized with three sentences, front-loading the core purpose. The second and third sentences about the deep link are relevant but could be more integrated. No wasted words, though slight redundancy in mentioning the link twice.

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?

Given no annotations and no output schema, the description is incomplete for a creation tool with 5 parameters. It covers the purpose and return behavior but misses critical context like error cases, side effects, or prerequisites (e.g., needing valid contactId from list-contacts). The schema handles parameters well, but overall guidance is minimal.

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 description coverage is 80%, so the baseline is 3. The description adds no parameter-specific information beyond what the schema provides (e.g., it doesn't explain 'lineItems' or 'type' further). It mentions the deep link return, but this relates to output, not input 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 specific action ('Create an invoice in Xero') and resource ('invoice'), distinguishing it from sibling tools like 'create-contact' or 'create-quote'. It also mentions the return value (a deep link), which adds specificity beyond just the verb.

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 no guidance on when to use this tool versus alternatives like 'update-invoice' or 'list-invoices'. It mentions the deep link should be displayed to the user, but this is a post-creation instruction, not usage context. No explicit when/when-not or alternative tools are referenced.

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