xero_attach_file

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states the tool attaches files but doesn't mention authentication requirements, rate limits, file size constraints, whether the operation is idempotent, what happens on failure, or what the response looks like. For a mutation tool with zero annotation coverage, this leaves significant behavioral gaps.

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 a single, efficient sentence that gets straight to the point with no wasted words. It's appropriately sized for a simple tool with two parameters, though it could be slightly more informative without sacrificing conciseness.

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?

For a mutation tool with no annotations and no output schema, the description is incomplete. It doesn't explain what happens after attachment, whether there are side effects, error conditions, or what the tool returns. Given the complexity of file attachment operations and lack of structured behavioral information, the description should provide more context about the operation's behavior and outcomes.

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 description doesn't add any parameter-specific information beyond what's already in the schema (which has 100% coverage). It mentions 'PDF, image' which relates to filePath but doesn't specify format constraints or supported file types beyond those examples. With complete schema coverage, the baseline is 3 even without additional parameter details in the description.

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 ('Attach a file') and target resource ('to an existing Xero bill'), with specific file types mentioned (PDF, image). It distinguishes from some siblings like 'xero_attach_file_to_invoice' by specifying 'bill' rather than 'invoice', but doesn't explicitly differentiate from other bill-related tools like 'xero_add_line_item_to_bill' or 'xero_submit_bill'.

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. It doesn't mention prerequisites (e.g., the bill must exist), when not to use it, or how it differs from similar tools like 'xero_attach_file_to_invoice' or 'xero_attach_file_to_expense' in the sibling list.

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