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

With no annotations, the description carries the full burden, and 'Pure CPU, instant' is a genuinely useful disclosure: no network, no side effects, fast execution. However, it omits what happens on a malformed JSONPath or invalid JSON (error vs empty result), and does not state whether the operation is strictly read-only.

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, zero filler, with the core action front-loaded and the performance characteristic as a trailing qualifier. Nothing could be removed without losing information.

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 two-parameter tool this is close to adequate, and it does hint at the return value (matched nodes). But it is silent on the notable schema asymmetry — 'path' is not required — and on error behavior, leaving real gaps for a tool with no output schema.

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 both parameters are documented in the schema and the baseline of 3 applies. The description adds no syntax hints for JSONPath or explanation of the fact that 'path' is optional while 'json' is required.

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?

States a specific verb (query), resource (a JSON document), and mechanism (JSONPath expression), plus the return shape (matched nodes). It is clearly distinct from siblings like json_validate, json_flatten, or json_merge, though it never names those alternatives explicitly.

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 or when-not-to-use guidance, and no routing to the many sibling JSON tools (json_flatten, json_merge, extract, json_validate). The agent must infer from the name alone whether this or a sibling is the right pick.

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