create_spending

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

With no annotations and no output schema, the description carries the full behavioral burden. It discloses that the tool records a new expense and implies foreign-key validation by requiring valid IDs from the list endpoints. However, it does not state what is returned on success, how invalid IDs fail, or whether duplicates are rejected — material gaps for a write operation with zero annotation coverage.

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 sentences with zero filler. The purpose is front-loaded in the first sentence and the prerequisite workflow in the second. Every word earns its place.

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 five-scalar-parameter create tool with full schema documentation, the description covers the purpose and the key prerequisite workflow. The only meaningful gap is the absence of return-value behavior, which matters more because neither annotations nor an output schema exist to fill it.

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%, setting the baseline at 3. The description adds real meaning beyond the schema by revealing that categoryId and sourceId are not arbitrary strings but foreign keys obtainable from list_spending_categories and list_spending_sources. This provenance information is genuinely useful and slightly exceeds the baseline.

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 verb and resource — "Record a new expense" — which clearly unambiguously separates this creation tool from sibling mutations like update_spending and delete_spending, and the word "expense" distinguishes it from create_income. It stops short of explicitly naming the sibling alternatives, so it is clear but not maximally differentiating.

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 gives an explicit precondition and workflow: call list_spending_categories and list_spending_sources first to obtain valid IDs, telling the agent exactly what setup is required before invocation. It does not state when to prefer alternatives such as create_income for income recording, so it misses the exclusion half of strong usage guidance.

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