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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is covered. The description adds the 'Requires expenses:write scope' authorization requirement, which is genuine value beyond the structured fields, but it omits whether the delete is permanent, cascades to related records, or returns anything.

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 sentences with zero filler; the operation is front-loaded and the permission requirement follows immediately. Nothing extraneous.

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 single-parameter delete with destructive/idempotent annotations and full schema coverage, the auth scope note makes the definition largely sufficient. It would be stronger with a word on permanence or side effects, but no critical gap prevents correct invocation.

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 coverage is 100% with the single 'id' parameter documented as 'Expense ID' with a UUID pattern. The description adds nothing beyond the schema's 'by ID' phrasing, so the baseline of 3 is appropriate.

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 and resource ('Delete an expense') scoped by identifier ('by ID'), which clearly separates it from create_expense, update_expense, and get_expense. No explicit sibling naming, but the purpose is unambiguous within the CRUD group.

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?

Usage is implied by the delete verb plus the required ID, and the stated scope requirement hints at a precondition. However, there is no explicit when-to-use guidance, no note about alternatives (e.g., soft-delete or update), and no warning that the operation is irreversible.

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