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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses genuinely useful behavior: text is sent only to LanguageTool's public API (data-handling transparency), a per-successful-call price of $0.002 USDC paid via x402 across Base/Solana/Arc, and that failed calls are not charged. This covers cost, authentication/payment model and failure billing that annotations cannot express.

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?

It is front-loaded with the core purpose and packs in output format, parameters, privacy and pricing without filler sentences that could be cut. It is dense and slightly overstuffed, but each clause carries information, so structure is good rather than flawless.

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?

An output schema already exists, yet the description also enumerates the return contents (message, offending text, position, up to five suggestions, rule/category, corrected text), which is somewhat redundant but not harmful. Privacy, size limits and payment model are covered; only edge cases like unsupported languages or rate limits are absent.

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 both parameters (text, language) are already fully documented. The description usefully restates the 20 KB limit and the 'auto' default for language, but adds no format details or examples beyond the schema, matching the baseline when the schema does the heavy lifting.

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 states a specific verb and resource (grammar, spelling and style check) and names the engine (LanguageTool), so an agent immediately knows what it does. It is clearly distinct from sibling text_* utilities like text_readability or text_tone, but it never explicitly routes to or away from any sibling, so it stops short of the 5 benchmark.

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 explicit when-to-use or when-not-to-use guidance, and no alternative tools are named despite a large family of text_* siblings. The intended use (check grammar in a body of text) is only implied by the purpose statement, leaving the agent to infer context.

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