budget_record

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

Annotations already declare readOnlyHint=false and idempotentHint=true, so the safety profile is covered. The description adds meaningful behavior beyond that: default pool is daily, excess daily quota or an exhausted daily pool is immediately covered by flex, and request_id should be reused on retries. It does not detail error handling or permission requirements beyond 'user-authorized'.

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?

Four short sentences, front-loaded with the purpose. Each sentence carries operational meaning: default pool, overflow behavior, and idempotent retry handling. There is no filler or 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?

For an 8-parameter mutating tool with no output schema, the definition omits key invocation details: whether to_pool is required for transfers, whether kind or date have defaults, and how optional fields like note and category are treated. The pool and request_id behavior are covered, but the gaps are significant for confident use across all transaction kinds.

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 description coverage is only 13%, so the description must compensate but explains only pool defaulting, overflow to flex, request_id reuse, and the kind values (expense, income, transfer). It leaves to_pool—critical for transfers—as well as date, note, and category unexplained, and does not state whether kind defaults when omitted.

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 states a specific verb and resource: 'Record user-authorized expense, income or transfer.' This clearly separates recording from read-oriented siblings such as budget_transactions and budget_summary, but it does not explicitly name or contrast with any sibling.

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?

It gives useful retry guidance ('Reuse request_id when retrying this same user request') and explains default pool behavior, which implies usage for recording authorized transactions. However, it never states when to use this instead of budget_reverse, budget_settle, or budget_adjust_pool, and provides no when-not conditions.

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