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

No annotations are provided, so the description carries the full behavioral burden. It does disclose source ('read from schema.org Product graphs'), default slug behavior, and that an empty array means no published Product JSON-LD, which is useful. However, it does not state whether it is read-only, whether it hits the network, caching behavior, or how countries not in the active list are handled beyond the schema's note.

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?

Front-loads purpose, then when-to-use, then example, then edge case. Four sentences, each doing work, though the schema.org source detail is somewhat technical for an agent. No significant waste.

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 read-only two-parameter lookup with no output schema, the description covers purpose, trigger, example invocation, and an important edge case (empty array semantics). Missing only a note on whether the call is side-effect free. Adequate for the tool's complexity.

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 100%, so the schema already documents both parameters in detail (slug defaults, country whitelist). The description adds an example call and mentions the default slug, but these largely repeat the schema's own examples and defaults. Baseline 3 is appropriate.

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+resource ('Returns Siigo's catalog of products/plans') and the scope (per country, price/currency/features). Sibling tools are named in the sibling list but the description does not differentiate itself from get_page_structured_data, which it is tightly coupled to.

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?

Explicitly says 'Use this when the user asks about pricing, plans, or what's included in each tier,' giving clear triggering context. No explicit when-not condition or direct routing to an alternative like get_page_structured_data.

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