Get rate history

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does disclose what the tool returns (series plus min/max/avg/current/change) and the time-window scope. It does not mention response ordering, error behavior, or whether any side effects exist, though the tool appears to be a read-only query.

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 exactly two sentences with no filler. The main function is front-loaded, and the list_houses pointer is a useful, concise addition. Every sentence 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?

The description covers the core purpose, the key inputs, and the content of the returned result well enough for a simple history query. With no output schema, it would benefit from specifying the exact response structure or result ordering, but the omission of the period default is acceptable because the schema already documents 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?

The input schema already provides 100% coverage with descriptions for all three parameters. The description adds value by clarifying that origin refers to an exchange house and by pointing to list_houses for valid origin IDs. It also reinforces that period maps to 'last N months', supplementing rather than repeating the 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 clearly identifies the tool's purpose: returning historical rate series and statistics for a given exchange house and currency over a time period. The phrase 'historical rate series and statistics (min/max/avg/current/change)' distinguishes it from a simple current-rate lookup, though it does not explicitly name sibling alternatives like get_rates.

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 provides clear context for when to use the tool: when historical rate data and summary statistics for a specific origin and currency are needed. It also gives a practical prerequisite by recommending list_houses for valid origin IDs. It does not, however, explicitly state when not to use this tool or compare it with siblings.

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