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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds useful context beyond the annotations: results are approved rather than live-scraped, and each result includes a title, official URL, and short summary.

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?

Two short sentences with no filler. The action and scope are front-loaded, and the live-scrape caveat is a single useful clause that 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?

With one required parameter, one optional parameter, 100% schema coverage, an output schema, and read-only annotations, nothing essential is missing. The description also explains the return shape and data-source caveat clearly.

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%, so the parameters are already documented. The phrase 'trust and inheritance-tax guidance' modestly reinforces the expected topic values, but the description does not add meaning for the optional jurisdiction filter beyond what the schema provides.

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: 'Retrieve approved GOV.UK/HMRC trust and inheritance-tax guidance by topic.' It clearly distinguishes the tool from siblings like get_companies_house_guidance, and the caveat 'Not a live scrape of GOV.UK' further differentiates its role.

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 gives clear context: use this for approved/cached HMRC guidance on trust and inheritance tax, and explicitly rules out live scraping. However, it does not explicitly name an alternative tool or provide a when-not-to-use condition beyond the live-scrape exclusion.

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