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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals that the tool normalizes output 'when possible' and positions it for pre-processing/storage, but it does not specify error handling or return format on invalid JSON. Adds useful context beyond a bare one-liner.

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?

The description is well-structured with a clear opening sentence followed by bullet-style 'Use when' and 'Do not use when' lists. Every sentence adds value, and the format aids scannability. No filler or redundant content.

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?

For a simple single-param tool with no output schema, the description covers purpose, usage contexts, exclusions, and normalization behavior. It lacks explicit return/error details, but the use-case framing and exclusions make it sufficiently complete for an agent to select and invoke correctly.

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 0%, so the description must compensate. It implies 'value' is the string to parse via 'Parse a string as JSON', but does not explicitly describe the parameter's meaning, edge cases, or accepted encodings. The schema only provides the type, so the description adds minimal semantic value beyond the tool name.

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 opens with a specific verb-resource pair: 'Parse a string as JSON to confirm it is well-formed and return a normalized representation when possible.' It clearly states what the tool does and distinguishes itself from sibling tools by explicitly excluding schema validation, Base64, and identifier format checks.

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 description provides explicit 'Use when' and 'Do not use when' sections, listing concrete scenarios and naming alternative tools (e.g., base64_encode, base64_decode). This is the gold standard for usage guidance.

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