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 fully covered. The description adds one genuinely new behavioral fact: results reflect the public directory's coverage, i.e. the tool is scoped to what iDevice lists. It says nothing about behavior for an unknown or ambiguous company name, which leaves a real gap for a lookup tool.

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, front-loaded with what the tool returns and followed by the calling instruction. The first sentence is a dense list but every element earns its place. Minor redundancy between the description's examples and the schema's examples.

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?

No output schema exists, so the description carries the burden of describing return values, and it does so field by field (identity fields, covered categories, per-product lifecycle/price/Guide link). Given a one-parameter, annotated, read-only lookup tool, an agent has everything it needs to call it 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?

With a single parameter and 100% schema description coverage, the schema already documents that 'company' accepts a name or key with matching examples. The description's example values duplicate that. Baseline 3 is appropriate; nothing beyond the schema is contributed.

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 names a specific resource — a company as iDevice's public directory lists it — and enumerates its payload (name, homepage, description, covered categories, and products with a Guide). That is far more precise than the title alone. It stops short of explicitly contrasting itself with product-level siblings like get_product or find_products, which is the only thing keeping it from a 5.

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 tells the agent how to call the tool ('Pass the company's name or key, for example 'oura' or 'Samsung''), which is useful, but never states when to reach for this versus a sibling such as compare_products or get_product. Usage context is implied by the entity type rather than spelled out, and no exclusions or prerequisites are given.

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