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

Annotations already declare destructiveHint=true, readOnlyHint=false, idempotentHint=false and openWorldHint=true, so 'destructive write operation' is redundant with structured data. The description does add the confirmation gate, but it omits consequences of deletion (reversibility, effect on linked timecards/expenses, error on already-deleted invoice given non-idempotency).

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 compact clauses, with the action and endpoint front-loaded before the limitations. No filler sentences, though the endpoint path duplicates information the schema parameters already imply.

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 destructive, non-idempotent mutation with no output schema, the description covers the confirmation requirement and target endpoint, which are the essentials. It still leaves gaps on failure behavior and side effects on related records, which matter for an irreversible operation.

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 86%, so the schema already documents confirm, account_id, base_url, tokens, etc. The description only echoes the confirm=true requirement and the account_id/invoice_id path placement, adding no syntax or format detail beyond the structured fields. Baseline 3 applies.

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?

States a specific verb (deletes) and resource (invoice) plus the exact endpoint POST /invoicing/:account_id/invoices/:invoice_id/delete, which leaves no ambiguity about scope. It does not, however, differentiate itself from sibling mutations such as mark_invoice_void or archive-style operations, which a reader must infer.

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 'Limitations' clause gives one actionable prerequisite (confirm=true), which is real usage guidance. It never says when to delete versus voiding or archiving an invoice, nor what state the invoice must be in, so the when-to-use decision against siblings is left to inference.

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