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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=true. The description adds value by specifying 'without writing cache rows' (confirming idempotence) and 'partner-specific ESB rules' (accounting for partner-dependent behavior). No contradiction exists.

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 of 20 words packs the core purpose, scope ('one or more'), live nature, partner-specific rules, and side-effect note. Every word earns its place with zero redundancy.

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 an output schema present, the description need not detail return values. It covers the primary purpose and key behavioral traits (live, no cache write). Given the moderate parameter count (7) and openWorldHint, it could briefly clarify how order_type or domain_years relate to pricing, but the schema already handles parameter descriptions. The combination is largely sufficient.

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 57% – several parameters already have descriptions (domains format, years range, order_type enum, partner_id optionality, domain_years per-domain, requirement_use_case purpose). The tool description does not elaborate on any parameter beyond 'one or more domains'. It adds minimal semantic value over the schema.

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 uses a specific verb ('Check') and resource ('live local pricing and availability for one or more domains'), with technical context ('partner-specific ESB rules', 'without writing cache rows'). This clearly distinguishes it from siblings like suggest_available_domains (suggestion) and get_domain_details (details on registered domains).

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 description implies real-time, side-effect-free use ('without writing cache rows', 'live'), but does not explicitly state when to use this tool over alternatives such as suggest_available_domains or get_domain_requirements. No when-not-to-use or alternative guidance is provided.

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