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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: it 'takes no arguments and returns static text,' telling the agent the call is cheap, deterministic, and content-fixed rather than dynamic.

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?

Purpose is front-loaded in the first clause, followed by content details, trigger conditions, and fallbacks in a logical order with no filler. It runs somewhat long as a single dense paragraph for what is a simple static-text tool, but every clause carries routing or content 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 no-argument, no-output-schema tool, the description covers what it returns (static contact/buying info), what it does not cover (prices, availability), and where to go instead. Nothing needed to invoke it correctly is missing.

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?

Zero-parameter tool, which sets the baseline at 4. The description confirms 'takes no arguments,' reinforcing the empty schema and preventing an agent from inventing filter parameters.

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 and resource ('get the two ways to buy... with contact details for each') and enumerates the actual content: retail via place_order/web shop and B2B wholesale via LINE with tier pricing and an application requirement. It explicitly distinguishes itself from get_catalog and ask_gyotak, so an agent can route correctly without opening any schema.

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?

Gives explicit trigger conditions ('when the user asks how to buy, how to open a wholesale account, or how to reach GYOTAK') and names the alternatives with their selecting conditions: get_catalog for availability/prices, ask_gyotak for other questions. Both when-to-use and when-not-to-use are covered.

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