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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so safety is covered. The description adds genuinely non-obvious behavioral context: that the ``summary`` totals cover ALL budgets for the month rather than just the returned page, plus the pagination metadata shape (total_count/has_more/offset/limit).

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?

Front-loaded with the core purpose, then organized into Args/Returns sections. Efficient overall, though the Args block restates defaults already present in the schema, adding mild redundancy.

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?

With no output schema, the description correctly fills the gap by describing the return payload and pagination metadata. All three parameters are documented, and the total-vs-page caveat covers the main ambiguity an agent would face.

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 0%, so the description must compensate, and it does: it documents all three parameters with the month format (YYYY-MM), the default-to-current-month behavior, the limit default of 50 with a max of 200, and the offset semantics. It largely duplicates the schema defaults but supplies missing format and bound constraints.

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 clear verb and resource: "List all budgets for the user." An agent knows exactly what it retrieves. However, it does not differentiate itself from related siblings such as get_budget_history, get_budget_streaks, or create_budget/update_budget/delete_budget.

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 never says when to use this tool versus alternatives like get_budget_history or get_budget_streaks, nor does it state prerequisites. It only describes the retrieval mechanics, leaving usage to be inferred from the name alone.

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