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

The description adds real context beyond the annotations: 'Free to call' signals no call-budget cost, and 'We review these every week and build the most-requested data first' discloses that this is an asynchronous request with no immediate data returned. Nothing contradicts readOnlyHint=false (a submission does create a record) or openWorldHint=false; auth and rate-limit details are absent but low-risk here.

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, front-loaded with the cost signal and then the qualifying condition, then the outcome. No restatement of the tool name and no wasted clauses.

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 fully documented, no-output-schema submission tool, the description covers purpose, trigger and what happens after submission. It could be slightly more complete by stating that no data is returned synchronously, but the weekly-review sentence conveys that implicitly.

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 schema already explains need, region and context fully. The description reinforces the one-sentence constraint on the required field but adds no meaning beyond the schema for the optional region and context parameters, 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?

The description states a specific action (describe a missing data need) and resource (South African cost, rate, rule, price or place not covered), and explicitly frames itself as the fallback when the sibling calculators don't cover a need. It is immediately distinguishable from bond_repayment, municipal_rates and the other siblings, which are lookups rather than submissions.

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 gives a clear trigger: use this when needed South African data is not provided by 'none of these tools,' and enumerates the kinds of gaps that qualify. It does not name the specific sibling domains, so an agent still has to reason about what the siblings already cover before deciding to fall back here.

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