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

With no annotations, the description carries full behavioral burden. It usefully discloses the detection method and the closed set of supported encodings, implicitly ruling out UTF-32 and statistical detection, but says nothing about error handling for non-hex input, ambiguity cases, or the response shape for a detect operation.

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?

A single tight sentence, front-loaded with the action and scope, ending with a high-value clarification. Every clause earns its place with no redundancy.

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 and no output schema, the description should ideally hint at return values (e.g., the detected encoding label) and the guarantees/limits of detection. It covers the core purpose adequately but leaves the result and edge-case behavior unspecified.

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?

The schema has 0% description coverage and the single parameter is a nested object, but the description does convey the key semantic that the input is hex-encoded bytes. It still omits the nested payload/hex_bytes structure and any format expectations (case, separators, odd-length input).

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 (Detect) plus resource (hex-encoded bytes) and an explicit scope: ASCII, UTF-8, or UTF-16-with-BOM. It further disambiguates the method ('decode-validity and BOM presence, not statistical language detection'), which cleanly separates it from generic encoding or language-detection tools.

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?

Usage is implied by the 'not statistical language detection' aside, but no explicit when-to-use or when-not guidance is given, and the sibling it pairs with (encoding_transcode) is never named. An agent can infer intent, but nothing routes it toward or away from alternatives.

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