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

With no annotations, the description carries the full burden. It usefully discloses the plan/auth requirement ('Requires a plan that includes the convert endpoint') and the default of returning all currencies unless filtered. It does not mention rate limits, pagination, or the nature of the returned payload, leaving meaningful behavioral gaps.

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 tight sentences with zero filler, front-loading what the tool does before the plan prerequisite. Every clause earns its place.

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 5-parameter tool with no annotations and no output schema, the description covers purpose and licensing but omits the return shape (e.g., a map of currency→converted value), which is not documented elsewhere. Adequate but with a clear gap given the absent output schema.

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%, so the schema fully documents date, type, value, currencies, and base_currency. The description reinforces the base-currency default and the all-vs-filtered behavior but adds no syntax or format detail beyond the schema. Baseline 3 is appropriate.

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 concrete verb and resource: 'Converts a value from the base currency into all (or a filtered set of) currencies.' The scope (today or historical date, filtered currencies) is specific and unambiguous. However, it never names or contrasts with its obvious siblings getHistorical and getLatest, leaving sibling differentiation to inference.

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?

Usage is only implied by 'for today or for a given historical date' and the plan prerequisite. There is no explicit guidance on when to pick getConvert over getLatest/getHistorical, nor exclusions. An agent can infer the conversion purpose but gets no routing help.

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