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

Discloses a lot beyond the annotations: per-call cost ($0.005 USDC via x402 on Base, errors free), the underlying model and fallback, Markdown-preserving block translation, auto-detection with `from` override, and a 20,000-char cap (default 8,000). Annotations already cover the safety profile, and the description adds pricing, model, and limit context on top.

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?

Front-loads the critical payment constraint before the functional description, which is the right priority. The long language list is bulky but earns its place since the schema exposes no enum; otherwise the prose is dense and waste-free.

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 output schema, the description should ideally state the return shape; it only implies it via 'translated in blocks, preserving Markdown formatting, URLs and code blocks.' Everything else an agent needs — cost, inputs, limits, languages, defaults — is covered.

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 baseline is 3, but the description adds real meaning: the enumerated list of supported target languages (filling the gap left by zero enums in the schema), the auto-detect default for `from`, and the char limit semantics. It goes beyond restating what the schema documents.

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+resource ('LLM translation (Meta Llama 4 Scout on Workers AI, M2M100 fallback)') and clarifies the two input modes (text vs. url main-content extraction). An agent can distinguish it from siblings like llm_chat, summarize, and url_to_markdown from the description alone.

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?

Clearly explains the conditions selecting each input mode: give `text`, or a `url` whose main content is extracted, and notes that with no params it translates a short Spanish sample. It does not explicitly name alternatives (e.g., when to prefer llm_chat or url_to_markdown), so it falls short of a 5.

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