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

The annotations already cover the safety profile (read-only, idempotent, non-destructive, open-world), so additional disclosure is optional. The description still adds real context: the source is the UK Parliament Bills API, the call costs one credit, and the tool deliberately does not forecast outcomes.

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 first sentence is long and front-loads the scope; the following sentences add only useful detail (example questions, source, prerequisite, exclusion, cost). Nothing is filler, though the opening sentence could be split for easier scanning.

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?

There is no output schema, and the description compensates by enumerating the fields that come back. Combined with the annotations covering safety and a fully documented single parameter, it gives enough information to call the tool correctly without guessing; only the exact response shape remains unspecified.

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 100%, and the schema already describes billId as the Parliament ID from bill_search with an example. The description's note that it needs the ID from bill_search largely restates the schema, adding little beyond the baseline.

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 names a specific resource and scope: the current state of a single UK bill, including stage, house, sitting dates, Act/withdrawn/defeated status, long title, and sponsors. It is clearly distinguishable from bill_search (which supplies the ID) and from timeline or amendment tools.

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?

It states the questions it answers ("where is the X bill now", "has it passed", "who introduced it"), requires that the bill ID come from bill_search, and explicitly excludes prediction of passage dates. It does not, however, route to sibling tools such as bill_stages_timeline or bill_amendments when those are better fits.

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