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

Beyond readOnlyHint/openWorldHint, the description discloses cost (4 credits, 1 credit = 1 CAD cent), that billing only occurs on successful calls, and that schema-invalid input is rejected pre-billing — genuinely useful economic and failure behavior. It also documents the return shape instead of leaving it opaque. It could still say whether long text is auto-chunked or how failures after billing are handled.

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?

Information is front-loaded: purpose first, then return shape, then pricing and validation behavior. Every sentence carries content (defaults, output keys, billing), with only mild verbosity in the parenthetical currency conversion.

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 3-parameter tool with no output schema, the description supplies the return fields, the billing model and the default language pair, which is close to complete. Remaining gaps are minor: no note on rate limits, text-length handling beyond the schema's 8,000 cap, or behavior on unsupported language codes.

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 documents text length, redaction, ISO 639-1 patterns and both defaults. The description only restates the default pair, adding no syntax or constraint detail beyond the schema — the correct baseline 3.

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 names a specific verb and resource ('Translates text between languages') and adds the operative default (en→fr for NS/NB customers), which immediately distinguishes it from nearby siblings like summarize, classify or sentiment. It stops short of naming any alternative tool, so it is clear but not fully self-differentiating.

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?

The customer-segment default implies typical usage, but there is no explicit when-to-use/when-not guidance and no routing to alternatives such as summarize or entity-extract. An agent can infer this is the translation tool but must decide on its own when translation is the right operation.

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