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

With no annotations, the description carries the full burden, and it does add real behavioral context: an external API key requirement and the constraint that edits preserve meaning and voice. It omits whether the tool rewrites aggressively, what the response contains (corrected text vs. change list), and how length limits 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?

One sentence, front-loaded with the action and the preservation constraint before the key requirement. The trailing vendor attribution '(API Tool Calls, by Cowerx)' is non-functional noise an agent cannot act on.

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?

No annotations and no output schema, so the description must carry behavioral and return-shape information; it covers the action and auth requirement but never says whether the result is corrected text, a diff, or a report — a meaningful gap for a rewrite tool. For a single-parameter tool this is adequate but not complete.

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% for the single 'text' parameter, so the schema already explains the input including the 2,000-word/15,000-character limit. The description adds no additional parameter semantics, which is the expected baseline for fully documented params.

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?

Specific verb plus enumerated resources: 'Fix spelling, grammar, punctuation and word choice,' with the invariants 'keeping meaning and voice.' No sibling tool (barcode, transcript, SEO, markdown conversion, etc.) overlaps with text correction, so there is no routing ambiguity to resolve.

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 'needs your OpenRouter key' clause states a genuine prerequisite for use, which is more than nothing. However, there is no when-to-use framing, no guidance on input shape or language coverage, and no mention of what to do with the result versus other tools.

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