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

Annotations declare readOnlyHint and openWorldHint, and the description adds rich behavioral context beyond them: it explains the _shopgraph metadata with provenance, freshness, and abstain fields, and explains how null values indicate verification failure. This gives the agent a clear model of what the tool returns and how to interpret trustworthiness, without contradicting annotations.

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?

The description is tight and well-structured: purpose in the first sentence, cost details in the second and third, and data quality metadata in the fourth. Every sentence contributes new information, with no redundancy or filler.

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?

Given the tool has 7 parameters and no output schema, the description covers essential context: the output's verification metadata, nulling behavior for unverifiable fields, and pricing. It could mention response structure in more detail, but the description is sufficiently complete for an agent to understand and trust the tool.

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 coverage is 100%, so parameters are fully documented in the schema. The description does not add parameter-specific details, but it does explain the overall output metadata (field_method, field_freshness, abstain) which helps understand the meaning of confidence-related parameters. This is baseline for high coverage.

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 'Extract' with a clear resource 'basic product attributes from a URL' and lists the exact fields (name, price, brand, availability). It distinguishes itself from the sibling enrich_product by explicitly noting it is 'Faster and cheaper', making the tool's purpose unambiguous.

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 provides clear context for when to use the tool by comparing with enrich_product ('Faster and cheaper') and mentioning the free tier/payment model. It doesn't explicitly state when not to use it or name all sibling alternatives, but the guidance is sufficient for basic selection decisions.

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