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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is fully covered before the description is read. The description adds the useful framing that content is authoritative 'in the shop's own words' and reads as static reference data, but says nothing about freshness, caching, or scope of the returned corpus.

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 sentences: the first front-loads the resource and its topic coverage, the second gives the usage condition. The topic list is long but each item is a distinct content category that helps an agent judge coverage, so it earns its space; only minor tightening is possible.

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?

An output schema exists, so the description need not explain return values, and its enumeration of covered topics tells the agent whether this tool can answer a given question. What remains missing is any hint about the shape/granularity of the returned facts or whether the corpus is complete, but for a zero-parameter reference lookup this is close to 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?

The tool takes no parameters, so there is no parameter semantics to explain and the baseline is 4. The description correctly does not waste space inventing arguments, instead describing what the fixed response contains.

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 resource (IbiPoint shop facts) and enumerates exactly what it covers: delivery/installation, device requirements, payment methods, guarantee, top-up, hotspot, support, company details. It also distinguishes itself from plan-specific siblings with the phrase 'not about one specific plan,' so an agent can tell it apart from get_plan_details without opening either 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 a clear triggering condition — any 'how / when / what if' question — and an explicit exclusion, questions about one specific plan, which implicitly routes the agent to get_plan_details. It stops short of naming the alternative tool or describing the boundary for other siblings (recommend_plan, start_checkout), so it is strong but not fully explicit routing.

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