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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds the one behavioral fact that matters (output is Indonesian words), but says nothing about handling of decimals, negatives, zero, or large values, which are realistic edge cases for a currency-word converter.

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?

One front-loaded sentence with zero filler, appropriate for a single-parameter utility. It is efficient but borders on under-specified rather than optimally sized.

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 one-parameter pure function with rich annotations, the description is minimally adequate. Missing details about decimal/negative handling and output format are the main gaps, though the lack of an output schema makes the return shape ambiguous enough to warrant a note.

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 0%, so the single 'amount' parameter is documented only by its name and type. The description does not clarify whether it accepts decimals, negative values, or a maximum magnitude, and does not specify the expected output wording conventions.

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 ('Convert') and a specific output form ('Indonesian words (terbilang)'), so the agent knows this produces spelled-out text rather than a formatted numeral. It does not, however, distinguish itself from the sibling format_rupiah or parse_rupiah, which an agent could easily confuse for this same task.

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?

There is no guidance on when to pick this over format_rupiah (numeral formatting) or parse_rupiah (the inverse direction). The agent must infer the routing decision entirely from the tool name.

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