monthly_summary

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 report's contents and the conditional budget-status behavior, and 'Get' clearly signals a read-only operation. It does not state exact response shape or behavior when no expenses are present, but these are minor for a simple summary tool.

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 well-structured sentence with the core purpose front-loaded and the conditional budget detail at the end. Every element earns its place and there is no redundant filler.

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 one-parameter, read-only reporting tool with no output schema, the description covers the required month format and the key return values. The only minor ambiguity is how the tool behaves when no budget has been set, but this does not block correct invocation.

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?

There is only one parameter and the schema already enforces its format via the YYYY-MM pattern. The description repeats this format but adds little semantic meaning beyond the schema, so it is adequate rather than additive.

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 opens with a specific action and resource ('Get a summary ... for a given month') and specifies the exact output contents (total plus per-category breakdown). This clearly separates it from the sibling tools, which are line-item, mutation, or configuration operations.

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?

Usage is implied ('Get a summary... for a given month') and the budget-status condition is noted, but no alternatives are named and no when-not-to-use guidance is given. With siblings like list_expenses and set_budget, explicitly routing to this tool for aggregate views rather than itemized lists would improve the guidance.

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