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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is known. The description adds value by disclosing an unexpected side behavior—retrieving live guardrails_blocked stats—and briefly mentions the method ('guardrail patterns'). This goes beyond structured fields, though it omits details about how stats are delivered or whether they affect the detection output.

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 two sentences with no filler. The first sets the primary action, and the second discloses a relevant secondary behavior. Both earn their place, and the structure is front-loaded with the core purpose.

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 one-parameter tool with an output schema and read-only annotations, this description covers the purpose, primary input, and a notable side effect. The only minor gap is the lack of elaboration on how the retrieved stats are presented, but the output schema likely handles that. Overall it is complete enough for an agent to 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?

The schema documents the single 'text' parameter with 100% coverage, so the description adds no new semantics beyond restating the parameter's purpose. It does not clarify format, length limits, or encoding, but the baseline of 3 is appropriate when the schema is sufficient.

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 clearly identifies the core action—detecting prompt injection attempts in text—using a specific verb and resource. However, the second sentence introduces a second purpose (retrieving live guardrails_blocked stats), which slightly dilutes focus and could confuse the agent about the tool's primary function. It still distinguishes itself from siblings by naming 'injection' specifically.

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 explicit guidance on when to use this tool versus alternatives like thinkneo_evaluate_guardrail or thinkneo_check. No exclusions, prerequisites, or example scenarios are provided, so the agent must infer applicability purely from the name and vague phrasing.

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