BoE base 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. It discloses the return fields (date, new rate, move in basis points) and specifies that the earliest known entry has a null move. This provides meaningful behavioral insight beyond the schema, though it does not mention ordering (e.g., descending chronological) or edge cases like limit exceeding available data.

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 a single, information-dense sentence that front-loads the core action and then specifies the output fields. Every word contributes value, with no redundancy or fluff.

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 tool with one parameter and a provided output schema, the description adequately covers what the tool returns. The null-handling note adds useful edge-case context. A minor gap is the lack of explicit statement about ordering, but this is inferable from 'last N changes'.

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 fully describes the 'limit' parameter, including default value and range. The description merely refers to it as 'N' without adding new semantics. Since schema coverage is 100%, the baseline score of 3 applies.

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 states the verb ('Get'), the resource ('Bank of England base rate changes'), and the scope ('last N'), with explicit output fields. It effectively distinguishes itself from sibling tools like get_current_rate and get_rate_at, which target a single point in time.

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 does not explicitly state when to use this tool versus alternatives or provide exclusionary guidance. However, the phrase 'last N changes' implies it is for historical change data, and siblings like get_current_rate imply current rate. The usage context is present but only implicitly.

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