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

Annotations already establish read-only and open-world behavior, so the bar is lower, and the description adds real context beyond them: the required auth scope ('vms.read') and the expectation that the agent surface prices to the user. It does not describe pagination, caching, or the shape of the returned price data, leaving a small gap for a read-only endpoint.

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 compact sentences plus a scope tag, front-loading the returned content and then the call-to-action. Every clause — the price granularities, the disk add-on price, the user-facing price display, the scope — carries operational weight with no filler.

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 no parameters and no output schema, the description carries the burden of explaining return content, and it does so by enumerating the categories returned including regional price granularity. It stops short of indicating how the response is organized (e.g., grouped by size or region), which would matter for an agent that must render prices.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. What parameter-like variability exists (region affecting prices) is at least mentioned in the returned content description.

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 enumerates exactly what the tool returns — engines, versions, extensions, sizes with hourly/monthly/yearly prices per region, and disk pricing — which is far more specific than the name 'get_database_options' alone. It lacks an explicit verb ('list'/'retrieve'), and its boundary against sibling catalog tools like list_plans and list_regions is left implicit.

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 states a concrete trigger ('Call it before create_database') and a follow-through action ('show the price to the user'), which is meaningful guidance for an agent planning a database workflow. It doesn't explicitly say when not to call it or how it differs from list_plans/list_regions, so it stops short of the top mark.

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