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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds that it returns an explanation of specific content areas, which is useful but not strictly behavioral. It doesn't contradict annotations and adds minimal extra context beyond the annotations. A 3 is appropriate.

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 a single sentence that is direct and front-loaded with 'Explain agentic commerce'. It is concise but somewhat dense, listing multiple topics in one breath. No redundant phrasing, but could be broken into clearer clauses. Overall efficient.

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 overview tool with one optional parameter, the description adequately covers what the tool returns. It doesn't specify the output format, but that is not critical given the read-only nature and the fact that no output schema exists. The parameter defaults are covered by the schema. It is complete enough for an agent to invoke 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?

The schema has 100% description coverage for the single 'section' parameter, including an enum and a clear description. The tool description adds no additional parameter semantics. With full schema coverage, the baseline is 3, and the description doesn't exceed that.

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 clearly states the tool 'explains agentic commerce' and enumerates its scope (shift, protocols, mechanism, market data). The verb 'explain' and the resource are specific. It does not explicitly differentiate from sibling tools like get_agentic_commerce_glossary, but the broad overview nature is inferable. A 4 because it's clear but lacks explicit sibling differentiation.

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?

There is no guidance on when to use this tool versus siblings. No mention of alternatives, conditions for use, or exclusions. The description only says what it does, not when to choose it over get_agentic_commerce_glossary, get_apirro_pricing, or scan_agent_readiness. This is a gap.

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