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

Annotations declare readOnlyHint=true so safety is covered. The description adds that it returns spending-vs-budget comparison for a month, a mildly useful behavioral detail, but says nothing about return format or how budget is compared.

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?

A single clean sentence, front-loaded with the primary action. No wasted padding, though it is arguably too terse for the missing usage guidance.

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 computed tool with no output schema, the description covers the core purpose but omits return shape and how status is derived, leaving gaps an agent would need to fill.

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 100% with all three params documented including examples. The description adds only the notion of 'specific month' scoping and currency context, no real meaning beyond the schema.

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 (get) and resource (budget status), plus clarifies it includes spending vs budget for a month. It is distinguishable from siblings like get_spending_summary, though it doesn't explicitly differentiate itself from get_balance_overview or get_spending_summary.

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?

No guidance on when to use this versus analogous siblings such as get_spending_summary or get_balance_overview. The only context is the 'specific month' scoping, leaving alternatives implicit.

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