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

No annotations are present, so the description carries the full burden, and it does add one genuinely useful behavioral fact: the free-trial quota tied to a signed wallet, which implies an auth/payment gate. Beyond that it says nothing about determinism, confidence scoring, supported languages, or output shape. Partial credit for the quota/auth disclosure, but substantial behavioral gaps remain.

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?

Two short sentences with the purpose front-loaded and no filler. The only waste is restating the tool name verbatim at the start, which costs a few tokens without adding information. Efficient overall.

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 annotations, no output schema, and two ambiguous optional parameters, the description should carry much more: what a result looks like (language name vs. ISO code, confidence), what happens on empty or ambiguous input, and which parameter to supply. The pricing note is the only context offered, so an agent cannot call this tool confidently.

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 nominally 100%, but the field descriptions are tautological ('Text to process' / 'Input to process') for two optional, apparently overlapping parameters. The tool description adds nothing to disambiguate 'text' from 'input' or to say which one the detector actually consumes. Baseline 3 applies when the schema nominally documents the parameters, but the ambiguity is unresolved anywhere.

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 ('Detect text language'), so an agent knows exactly what the tool produces. However, it does not distinguish itself from near-identical siblings such as x402-language-guess, x402-ai-language, or x402-language-by-country, leaving the agent unable to pick between them. The leading name repetition is redundant but not misleading.

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 when-to-use guidance, no prerequisites, and no mention of the competing language-detection siblings. The only extra sentence covers billing ('5 free trial calls per signed wallet'), which is a cost/auth fact rather than usage routing. An agent has no signal for choosing this tool over the alternatives.

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