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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=false, covering the mutation/safety profile. The description adds one genuinely useful non-annotation fact, the required expenses:write scope, but says nothing about idempotency behavior, side effects on related entities, or validation failures.

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 short, front-loaded sentences with zero filler; the action is stated first and the scope requirement second. It is efficient, though it leans toward under-specification rather than tight completeness.

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 an 8-parameter mutation tool with no output schema, the description is thin: no return-value expectations, no note on how optional category_id/work_order_id/receipt_url are handled, and no failure-mode guidance. Only the auth scope requirement is supplied beyond what the schema and annotations already give.

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% across all 8 parameters, so the schema already documents names, types, required flags, and formats. The description adds no parameter-level meaning beyond that, so the 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 + resource ('Create a new expense'), which is unambiguous on its own. However, it offers no differentiation from the many sibling write tools (bulk_create, create_invoice, create_purchase_order, update_expense, etc.), so an agent must infer which creation endpoint fits from the name alone.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives. The agent is told what the tool does but not when to prefer it over siblings like bulk_create or create_invoice.

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