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

With no annotations, the description carries the full burden. It does disclose real behavioral traits — no submission side effects and the FAQPage edge-case — but omits return format, whether either parameter alone suffices, and any auth/rate-limit context.

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?

Three short sentences, front-loaded with the core purpose and followed by tightly scoped disclaimers. Each sentence carries distinct information with no redundancy.

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 tool with no output schema and 0 required parameters, the description should say more about expected inputs/outputs and how url vs json interact. The boundary clarifications are useful, but the calling contract for the two optional params is left unresolved.

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 only 50% (url documented as 'Public http(s) URL.', json undocumented), and the description says nothing about the two parameters, their relationship, or whether url and json are alternatives. It does not compensate for the coverage gap.

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 verb (validate), resource (JSON-LD / schema.org markup), and the standard it checks against (Rich Results eligibility). It implicitly distinguishes itself from generate_schema through the verb, but never names siblings explicitly.

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 exclusions ('does NOT submit to Google', 'does NOT measure whether rich results appear in search') usefully bound the tool and hint that other tools cover those needs, but no alternative tool is named and there is no explicit when-to-use condition or prerequisite.

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