update-manual-journal

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

No annotations are provided, so the description carries the full burden. It discloses key behavioral traits: the tool only works on draft journals and should not modify unspecified parameters, which are important constraints. However, it lacks details on permissions, error handling, or mutation effects (e.g., whether updates are reversible), leaving gaps in behavioral 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 main purpose and followed by critical constraints. Every sentence earns its place by providing essential information without redundancy or fluff, making it highly efficient and well-structured.

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 the complexity (8 parameters, no annotations, no output schema), the description is adequate but incomplete. It covers key usage constraints but lacks details on return values, error cases, or broader context (e.g., how it fits with other Xero operations). For a mutation tool with no structured safety hints, more behavioral disclosure would be beneficial.

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 100%, so the schema fully documents all parameters. The description does not add any additional meaning or syntax details beyond what the schema provides (e.g., it doesn't explain parameter interactions or provide examples). Thus, it meets the baseline but adds no extra value.

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 action ('Update a manual journal in Xero') and resource ('manual journal'), making the purpose explicit. However, it does not distinguish this tool from sibling tools like 'update-bank-transaction' or 'update-invoice', which also perform updates in Xero, so it lacks sibling differentiation.

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 context for when to use this tool ('Only works on draft manual journals') and includes a constraint ('Do not modify line items or parameters that have not been specified by the user'). However, it does not explicitly mention alternatives (e.g., 'create-manual-journal' for new journals or other update tools for different resources), so it falls short of full explicit guidance.

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