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

With no annotations, the description carries the full behavioral burden. It usefully discloses the key trait — validation only, no remote invocation — but says nothing about failure behavior, whether an unknown/unindexed tool name errors, or whether the result reports a pass/fail flag or a list of schema violations.

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 with zero filler, and the non-invocation guarantee is placed immediately after the core purpose where it matters most.

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 describe the shape of the validation result (valid/invalid, error list). It only says 'an example-validation result', leaving the return contract underspecified for a tool whose entire value is its verdict.

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 does map the parameters conceptually — serverName/toolName identify the indexed target tool and 'arguments' are the sample payload to check — but adds no format, length, or lookup guidance beyond that.

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 (validate) and a specific resource (sample arguments against an indexed MCP tool input schema), which is far more than a restatement of the name. No sibling does schema validation, so no differentiation is strictly needed, though the description never says how this relates to the capability-test siblings.

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 phrase 'never invokes the remote tool' implies the use case (dry-run argument checking before a real call), but the description never states when to reach for this tool versus just calling the target tool, nor any prerequisite such as the tool already being indexed.

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