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

Beyond the annotations' destructiveHint=true, the description discloses that there is no recycle bin, the action cannot be undone, and it lowers the project's cost. It also reveals permission constraints and the critical rule that the agent must never fill in confirm/confirmation_phrase on its own. This is rich, safety-critical behavioral disclosure.

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 compact and front-loaded with the most important fact: permanence. Every sentence contributes essential safety, permission, or batching guidance. There is no filler or repetition of the schema.

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?

Despite having no output schema, the description covers everything an agent needs to invoke this destructive tool safely: permanence, irreversibility, cost impact, ownership permissions, human-confirmation requirements, and batch behavior. The tool's complexity and risk are fully addressed.

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 baseline is 3. The description adds practical usage semantics: expense_ids should be used for a batch under a single confirmation, and confirm/confirmation_phrase must only be supplied by the human. This goes beyond the raw schema property descriptions and helps the agent handle the single-vs-batch distinction.

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 begins with 'PERMANENTLY delete one or more expenses,' naming the specific verb, resource, and irreversible nature. This clearly distinguishes it from timelog_update_expense and timelog_add_expense, and the resource 'expenses' separates it from timelog_delete_entry.

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 gives clear context: it is for deleting expenses, can only delete your own unless you hold the right scope, and requires explicit human confirmation. It advises using the batch expense_ids parameter instead of one call per row. It does not explicitly name alternatives like timelog_update_expense for non-destructive changes, so it stops short of a full when-not-to-use statement.

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