Detect Recurring Charges

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description adds meaningful behavioral context: it cross-references with scheduled transactions, returns suggestions only ('create_scheduled_actions for unmatched recurring charges (suggestions only)'), and flags price changes. This extra detail helps the agent understand the tool's behavior beyond 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 concise: two sentences, front-loaded with the main purpose, and the second sentence adds key details (cross-references, suggestions). No superfluous words, every sentence earns its place.

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 read-only analysis tool with no output schema, the description covers core functionality (analysis, frequency, price changes, cross-referencing, suggestions). It could mention the return structure more explicitly, but overall it provides sufficient context given the tool's complexity and the rich parameter descriptions.

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 100% with descriptions for all 4 parameters. The description adds marginal value by implying the role of history_months and min_occurrences in analysis, but does not provide additional specifics beyond what the schema already offers. Baseline 3 is appropriate given full schema coverage.

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's purpose: 'Identify subscriptions and recurring charges from transaction patterns.' It details specific actions: analyzing history, estimating frequency, flagging price changes, and cross-referencing with scheduled transactions. This distinguishes it from siblings like detect_anomalies (which detects anomalies) and search_transactions (which searches for transactions).

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 implies usage for detecting regular outflows and subscriptions but does not explicitly state when to use this tool versus alternatives like search_transactions or detect_anomalies. No 'when not to use' guidance is provided, making it somewhat vague for an agent deciding between sibling tools.

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