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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety of the operation is covered. The description adds genuine value with 'without executing code,' signalling no eval/expression semantics, but it omits what happens when the pointer does not resolve or when the path is malformed.

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 sentence with no wasted words, and the safety qualifier is placed where it matters most. Nothing is buried or redundant.

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 read tool with no output schema, the definition covers the core idea but leaves return behavior unspecified, including what a successful lookup yields and what a missing path produces. That gap matters more here precisely because there is no output schema to fall back on.

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 carry the load. It does add meaning by naming RFC 6901 for 'pointer' (implying '/'-separated tokens and ~0/~1 escaping) and by framing 'value' as arbitrary JSON data, but it says nothing about the root-pointer empty-string case or the accepted input types beyond 'JSON data.'

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 has a concrete verb ('look up'), a named resource ('RFC 6901 path in JSON data'), and a scoping qualifier ('without executing code'). It is clear what the tool does, though it does not distinguish itself from any sibling since none of the listed siblings are competing lookup 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 only implied: an agent can infer this is for extracting a nested value by path, but the description states no when-to-use conditions, no exclusions, and names no alternative. With no obvious sibling overlap that is defensible, but nothing actively guides selection.

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