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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description does add scope-limiting behavior: it returns review conditions and timing rather than a definitive answer, and it explicitly 'does not choose a spouse option or an election,' which tells the agent not to treat the result as an election decision. It says nothing about how 'unsure' enum inputs are handled, which matters for a 12-param determination tool.

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?

It is short, but it opens with a low-value meta-statement about an 'existing sourced calculator' instead of front-loading what the tool determines. 'It does not choose a spouse option or an election' is also underspecified — an agent cannot tell what an 'election' refers to here.

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 12-parameter determination tool with no output schema, the description should at least characterize the shape of 'review conditions and timing' and note that optional/unsure inputs are tolerated. Instead it gives a one-line nod to returns and leaves the caller to infer the rest, which is adequate but thin.

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% with enums on 8 of 12 params, so the schema carries parameter meaning. The description only confirms that previous_dec31_balance is optional and only needed for dollar amounts, which is a marginal but real addition over the schema's own wording.

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 name and title identify the domain (inherited IRA rules/schedule) and the description adds that it returns 'review conditions and timing,' which hints at a rules/determination output. But the lead sentence — 'Use the existing sourced calculator' — describes an implementation choice rather than what the tool computes, and no sibling (state_rules, after_death_deadlines, readiness_checklist) is differentiated from it.

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?

'Use the existing sourced calculator' is a directive with no when-to-use condition and no named alternative, so an agent cannot tell when this beats state_rules or after_death_deadlines. The one real precondition given — dollar amounts need an optional prior December 31 balance — is useful but is a data requirement, not usage routing.

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