monthly_trend

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

With no annotations, the description carries the full burden of behavioral disclosure. It does disclose ordering (oldest-first) and a limit (most recent N), which is useful. However, it does not explain the default behavior when 'limit' is omitted, nor does it clarify what 'per month' means (calendar months, rolling 30 days, etc.). It also doesn't mention that this is a read-only operation, though that is implied.

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, compact sentence: 'Spend + income per month (most recent N, oldest-first).' It is front-loaded with the core purpose and includes behavioral details without any fluff. Every word earns its place, making it highly concise and well-structured.

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 lack of annotations and output schema, the description is underspecified. It doesn't clarify the default value of 'limit', what the output structure looks like, or how spend and income are combined (e.g., separate series or net amount). The tool appears simple, but the missing details could lead to incorrect usage or interpretation.

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?

The schema has zero description for the 'limit' parameter, so the tool description must compensate. The phrase 'most recent N' directly connects the parameter to the behavior, indicating that 'limit' controls how many months are returned. However, it doesn't explicitly state the parameter's name or provide details like allowed values or default, leaving some ambiguity.

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 identifies the resource: spend and income per month, with scope (most recent N, oldest-first). It doesn't include an explicit verb like 'get' or 'list', but the meaning is clear and it distinguishes itself from sibling tools by focusing on monthly trends rather than single-month or category-specific views.

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 provides no guidance on when to use this tool versus alternatives. It does not mention any exclusions or reference sibling tools like 'get_month_summary' or 'compare_periods', leaving the agent to infer usage solely from the tool's name and vague description.

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