monthly_summary

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

Annotations already declare readOnlyHint=true, so the behavior is known to be read-only. The description adds the specific metrics shown (income, expenses, savings, rate) but does not disclose any additional behavioral traits such as pagination, sorting, or whether data is aggregated across all accounts. It adds some value but not deeply.

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 concise sentences with no redundant information. Every word adds value, stating the tool's output and its benefit. Efficiently 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?

For a simple read-only tool with one parameter and no output schema, the description adequately covers the purpose and metrics. It does not detail return format or edge cases, but given the low complexity, it is sufficiently complete.

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% for the single parameter 'months', so the baseline is 3. The description does not add extra meaning beyond what the schema already provides; it merely reinforces the parameter's role in controlling the number of months shown.

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?

Description clearly states it produces a monthly financial summary with specific metrics (income, expenses, savings, savings rate) across multiple months. This distinguishes it from sibling tools like balance_history (trends of a single metric) or category_trends (category-level trends). Verb+resource is explicit.

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?

Description indicates it's for seeing trends in overall financial health, which guides when to use it. However, it does not explicitly state when not to use it or direct to alternatives, but the purpose is sufficiently clear given the context of sibling tools.

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