upsert_crypto_synced_balance_history

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

The description discloses significant behavioral traits beyond the idempotentHint annotation: all-or-nothing atomicity, symbol matching requirement, and past-month validation. These are critical for safe and correct invocation and do not contradict the annotation.

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 three concise sentences with no filler. It front-loads the purpose first and then lists essential constraints, earning every sentence's 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 tool with a complete schema and idempotent annotation, the description covers all necessary behavioral context: operation type, temporal constraint, validation rule, and transaction atomicity. No critical invocation details are missing.

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%, so baseline is 3. The description adds cross-parameter constraints (symbol must match the argument) and array-level atomicity, which are not fully captured in the schema, providing meaningful additional parameter semantics.

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?

Description uses a specific verb+resource+scope: 'Create or update monthly balance history entries for a synced crypto holding.' It clearly distinguishes this from siblings like upsert_account_balance_history by specifying 'synced crypto holding' and adds key constraints.

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?

Clear context is provided ('synced crypto holding' and 'past calendar month') and the all-or-nothing behavior gives important usage guidance. However, it does not explicitly name alternative tools for other account types or state when not to use this tool, so it falls short of a perfect score.

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