detect_recurring_charges

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

No annotations are provided, so the description carries the full burden. It discloses the heuristic (amounts within 5% of average, at least min_occurrences times), which is valuable behavioral insight. However, it doesn't mention permissions, whether it's read-only, or output format.

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 sentences, front-loaded with the core purpose, then the heuristic detail. Efficient and no wasted words, though slightly dense.

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?

No output schema exists, so the description should explain return values, but it does not. It covers the input heuristic and usage context adequately but leaves gaps on output and permissions for a detection tool with no annotations.

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 description coverage is 100%, so the schema already documents all three parameters thoroughly. The description references min_occurrences but adds no syntax or format details beyond what the schema provides, so baseline 3 is 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 ('Flags'), resource ('payees that bill a consistent amount repeatedly'), and scope ('last several months'). Distinguishes itself from siblings like top_payees or spending_trend by naming the recurring/subscription detection intent explicitly.

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 conveys implied usage ('useful for spotting subscriptions, including ones you may have forgotten about'), which gives some context for when this tool is relevant. However, it doesn't name alternatives or explicitly state when not to use it versus tools like top_payees or search_transactions.

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