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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, which cover the safety and mutability profile. The description adds 'Deterministic text,' which reinforces the idempotent nature but does not introduce new behavioral details such as output structure or length. Some content context is added, but it's more about purpose than behavior.

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 concise sentences. The first states the action and topic; the second gives explicit usage guidance. There is no redundancy or vague language—every sentence earns its place.

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 zero-parameter, deterministic text explainer, the description sufficiently covers what it returns, when to use it, and the topic content. Annotations cover safety. There is no output schema, but the description's mention of 'explainer' and the specific content provides adequate context for a tool of this simplicity.

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?

This tool has zero parameters, so the schema is fully complete. The description does not need to explain parameter meanings, and the baseline for no-parameter tools is 4. There is nothing to add beyond what the schema already provides.

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 states the action ('Return an explainer') and the specific topic (paradigm integration via F2I/I2F primitives), which distinguishes it from sibling tools like explain_three_primitives and run_valdez_tanker. It includes a specific verb and resource, making the purpose unambiguous.

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?

It explicitly states when to use the tool: when the user asks about Valdez-Tanker-style mixed-paradigm systems or 'how do flows and items coexist'. This provides clear trigger conditions. It does not explicitly mention when not to use it or name alternatives, so it stops short of a 5.

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