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

Annotations already declare readOnly=false, destructive=false, and idempotent=false, so the safety profile is covered. The description adds the useful scoping detail that categorization applies to 'future' transactions only, but it does not explain precedence against existing rules or error behavior, and the confirmation note merely restates a schema requirement.

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, front-loaded with the purpose and ending with the confirmation precondition. It is efficient, though the 'Requires confirmation: true' clause largely duplicates the schema's confirmation field description.

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?

With five parameters, a mutation annotation profile, and no output schema, the description covers the essentials: purpose, temporal scope, and the confirmation gate. It leaves gaps around rule conflicts with existing rules and what is returned on success, which an agent would benefit from knowing.

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 80%, so pattern, match_type, confirmation, and idempotencyKey are already documented in the schema. The description adds no syntax, format, or matching-behavior detail beyond what the schema provides, making the baseline 3 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 ('Create a rule') plus the effect ('auto-categorize future transactions matching a pattern'), which tells the agent this is not the same as create_category. It does not explicitly distinguish itself from the closely related create_category_rules_bulk sibling, so it falls short of a 5.

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 when-to-use is implied by 'future transactions matching a pattern', and the confirmation gate is noted. But there is no guidance on when to prefer this over create_category_rules_bulk, or whether existing historical transactions are affected.

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