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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds value by detailing the specific data returned (limits, spent, remaining, projected) and the notion of a 'current period' and 'projected spending by end of period,' which goes beyond the annotation. It does not contradict annotations.

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 sentence that is clear and front-loaded with the primary purpose. It avoids fluff and effectively conveys the tool's output in a compact form.

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?

The description is sufficient for a simple list tool with no parameters and an output schema present. It covers the key output fields but does not specify the definition of 'current period' or whether archived/inactive budgets are included. These are minor gaps given the tool's simplicity.

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 tool has zero parameters and the schema is empty, so there is no parameter semantics to cover. Baseline is 4 given no parameters, and the description adds no parameter-related information, which is acceptable.

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 states the tool's function: showing budgets with limits, spent, remaining, and projected spending. The verb 'Shows' and resource 'budgets' are specific, and the listed fields distinguish it from other list tools like list_accounts or list_transactions.

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 implies that this tool is for retrieving budget information, but it does not explicitly contrast it with siblings like summary or other list tools. There is no guidance on when to use this versus alternatives, leaving the agent to infer usage from context.

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