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

With no annotations, the description carries the full burden. It usefully discloses the paid x402 pricing ($0.001/call, USDC on eip155:8453) and that error messages are precise, but it never says what happens on malformed JSON, whether the three operations run together in one call, or what the response looks like for each mode.

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 capability sentence is tight and front-loaded, with no filler. The trailing x402 price clause is legitimately useful meta-information for a paid tool but does interrupt the description, so it is not perfectly economical.

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 output schema and no annotations, the description should cover return and failure behavior. It sketches the outputs (top-level type, element counts) but omits the error path for invalid JSON and the interaction between the three advertised operations, leaving gaps for a tool with two required parameters and no structured safety metadata.

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 the baseline is 3. Both schema descriptions are terse ('JSON', 'Indent spaces'); the description adds 'any indent' but does not clarify the indent unit, valid range, or whether indent is irrelevant when only validating, so it adds little beyond the schema.

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 names three concrete operations (validate, pretty-print, inspect top-level type/element counts) on a specific resource (JSON), which is far more than a restatement of the name. It does not explicitly contrast with any sibling, but the sibling list contains no other JSON tool, so differentiation is implicit rather than stated.

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 listed capabilities imply when the tool is useful, but there is no explicit guidance on when to prefer this over alternatives, no noted prerequisites, and no statement about which inputs are required for a validate-only vs pretty-print call. Usage is inferable but not spelled out.

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