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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely new behavioural context the annotations cannot: the data is normally present in a Heirs context block, this call is only a refresh mechanism, and that block can be truncated — which explains why the tool may return incomplete-looking or duplicate 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?

Two sentences, zero padding. The 'what it returns' clause leads and the usage constraint follows, so nothing has to be read twice.

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 single-parameter read-only list with no output schema, the description is nearly sufficient — it names the fields returned and the refresh-only purpose. It could say slightly more about return shape (ordering, pagination) if the list can grow large, but nothing blocking is missing.

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 coverage is 100% and the single estate_id parameter is fully documented in the schema, including the instruction to call list_my_estates first. The description adds no parameter-level meaning beyond that, so the baseline 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?

States a specific verb and resource ('List every recorded heir') and immediately scopes what is returned ('with relationship and details'). It also implicitly distinguishes itself from mutating siblings like create_heir/update_heir by framing this as the read path.

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?

Gives an explicit when-to-call rule: 'call this only to refresh after adding or updating an heir, or when that block was truncated.' It also names the alternative source of the same data (the Heirs context block), which is exactly the when-not guidance an agent needs.

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