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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds conditional availability language—'where available' and 'where one has been collected'—which warns that some fields may be absent depending on data completeness. This is useful beyond the annotations.

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 long sentence but is front-loaded with the core action ('Get one insurer by slug') and then packs the remaining space with a useful, non-redundant list of returned fields. It is efficient and has no filler, though it is slightly dense.

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?

An output schema exists, so return-value documentation is covered structurally. The description still conveys the breadth of the record (parent group, regulator, identifiers, profile data, etc.) and the conditional nature of some fields, which is sufficient for an agent to know what to expect.

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 slug parameter is already fully documented with type, pattern, maxLength, minLength, and an example. The description adds no additional parameter-level meaning, so the baseline 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 opens with a specific verb and resource—'Get one insurer by slug'—and then enumerates the exact fields returned. This clearly distinguishes it from sibling tools like list_insurers (plural listing) and search_insurers (fuzzy lookup) by narrowing scope to a single known identifier.

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 phrase 'by slug' gives clear context: use this tool when you already have a stable slug identifier. It does not explicitly name alternatives or state when-not-to-use, but the singular and identifier-based framing makes the intended use obvious.

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