get_cpih_inflation_headline

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

The description explains the output (latest CPIH index month-on-month % change) but does not mention read-only nature, authorization needs, or rate limits. Since no annotations are provided, the description carries the burden; it is adequate but not comprehensive.

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 concise sentence that front-loads the key purpose. However, it omits important details about parameter and usage, which limits its effectiveness despite the brevity.

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 the existence of an output schema, the description does not need to explain return values. However, it is missing parameter information and usage context. For a simple tool, it is minimally adequate but leaves gaps for a agent making selection decisions.

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 has one optional parameter with no description and 0% schema coverage. The description does not explain the parameter at all, only mentioning 'dataset_id' implicitly via the default 'cpih01'. The description fails to compensate for the lack of schema documentation.

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 tool retrieves the latest CPIH index month-on-month % change from ONS observations, specifying it is a UK aggregate slice. This distinguishes it from sibling tools like get_ons_observations and get_ons_latest_version.

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?

No guidance on when to use this tool versus alternatives. With many sibling ONS tools, the description should indicate when this is the appropriate choice, but it does not.

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