create_price

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

The description adds substantial behavioral context beyond the sparse annotations: existing prices are updated rather than duplicated, currency defaults to the book's currency with a worked example, date and source default, and price_type values are enumerated. This is exactly the kind of surprise-preventing behavior an agent needs.

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 front-loads the core operation and the critical upsert semantics, then uses a compact Args block. There is no filler; the example is purposeful and the structure makes the details easy to scan.

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?

Given an output schema exists and annotations cover the non-read-only nature, the description supplies everything needed to invoke the tool correctly: defaults, edge cases, examples, and valid price_type values. No important behavioral or parameter-related information is 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 description coverage is 0%, but the description fully compensates: every parameter is explained with formats, examples, defaults, and allowed values. The currency explanation and the 'USD = 7.30 CNY' example add meaning far beyond the raw 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?

The description opens with a specific verb and resource: 'Record a price for a commodity (stock, NAV, exchange rate).' It clearly conveys that this is a single-price write operation and contrasts naturally with siblings like get_prices, delete_price, and create_prices.

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 purpose is clear enough that an agent can infer when to use it, and the upsert behavior is stated. However, it never explicitly tells the agent when to prefer this over the sibling create_prices, or when to use the price-querying siblings instead. The guidance is implied rather than explicit.

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