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

Annotations already declare destructive behavior and non-read-only intent, so the description only needs to add context, and it does: eligibility preconditions, the system-category restriction, and a pre-migration path. It does not spell out exact error behavior when constraints are violated, but the annotations and output schema cover the core safety profile.

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?

Three dense sentences carry only necessary information, with the action and primary precondition first followed by the exception and ID source. No filler or redundancy.

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?

Given a single required parameter, full schema coverage, annotations for safety/idempotence, and an output schema, the description provides the missing operational context: preconditions, system-category exclusion, the transaction-migration alternative, and where IDs come from.

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 schema already documents the single id parameter at 100% coverage, so the baseline is 3. The description's 'Category IDs come from list_categories' largely repeats the schema's 'see list_categories' and adds no new format or source detail.

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 uses a specific verb and resource ('Deletes a category') and immediately adds the defining constraints: no transaction use and no subcategories. This clearly distinguishes the operation from other delete tools and from update_transaction.

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 states when deletion is valid ('no transaction uses', 'no subcategories'), when it is not valid ('System categories cannot be deleted'), and the alternative workflow for moving transactions first with update_transaction. It also directs the agent to list_categories for valid IDs.

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