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

Beyond annotations (readOnlyHint=false, destructiveHint=false), the description reveals a critical behavioral trait: recategorizing automatically creates a Category Rule that affects future transactions. This is valuable context not available from annotations alone.

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?

Description is well-structured and front-loaded with the core purpose. It uses clear sentences, but could be slightly more concise by removing minor redundancies (e.g., 'teaches Pluggy' phrasing is clear but adds length). Still very effective.

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 mutation tool with no output schema, description provides complete context: input format, source of IDs, side effects (rule creation), and batch response structure (updated, results, errors). This covers all necessary aspects for an AI agent to invoke correctly.

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 0%, so description fully compensates. It explains the 'items' array structure, each field's purpose and origin (transaction_id from openfinance_list_transactions, category_id from openfinance_list_categories), and the batch response format.

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 action: 'Corrects the category of one or more transactions' via PATCH /transactions/:id. It specifies the resource (transactions) and action (update category), and distinguishes from sibling tools like openfinance_list_transactions and openfinance_list_categories by explaining where input IDs come from.

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?

Provides explicit guidance on when to use: to fix miscategorized transactions and improve future categorization. It tells how to structure the 'items' array and where to source transaction_id and category_id. Does not explicitly state when not to use, but the context is clear enough.

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