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

Beyond the annotations that merely indicate non-read-only, non-idempotent, and non-destructive, the description reveals a critical side effect: recategorizing automatically creates a Category Rule that affects future similar transactions. It also details batch error handling, describing the response structure and emphasizing that per-item errors do not fail the whole batch. No contradiction with annotations.

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 a single paragraph that efficiently conveys the purpose, parameter structure, side effect, and batch behavior. It front-loads the action and uses clear language. While it packs a lot of information, it is not overly verbose and every sentence adds value.

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 the tool's simplicity (one parameter, no output schema), the description covers input semantics, behavioral implications, and response format. It includes error handling details absent from the schema. No gaps remain for an agent to operate effectively.

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?

With 0% schema description coverage, the description fully compensates by explaining the structure of the `items` array and the meaning of each field, including the sources of transaction_id and category_id. This adds essential meaning that the raw schema lacks.

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 clearly states the tool corrects transaction categories, names the HTTP method and endpoint, and distinguishes itself from sibling tools by referencing openfinance_list_transactions and openfinance_list_categories for input IDs. It also explains the side effect of creating a Category Rule, which is unique to this tool.

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 explicitly advises when to use: 'to fix miscategorized transactions and improve categorization accuracy going forward.' It also provides guidance on obtaining the required IDs from other tools. However, it does not explicitly state when not to use or list alternatives, though the sibling context implies no other tool modifies categories.

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