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

With no annotations, the description must carry the behavioral load. It does disclose the key output shape ('return a corrected JSON-LD block') and the validation scope, but says nothing about whether the fetch is read-only, how failures are reported, or how long a run takes.

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?

One front-loaded sentence with no filler; the enumeration of supported schema types is long but earns its place by defining validation scope. Slightly list-heavy but not padded.

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 one-parameter tool with no output schema or annotations, the description covers inputs (a page), scope (extraction plus eight schema types), and the return value (corrected JSON-LD). Only the interpretation of validation results remains unclear.

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% and the single url parameter is documented with a full-URL example, so the description need not repeat it. Adding nothing about the parameter is acceptable at this coverage level.

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?

Description gives specific verbs (extract, validate, return) and a precise resource (JSON-LD and microdata schema markup on a page), plus an explicit list of supported types. An agent can tell it apart from validate_sitemap and check_entity, though the differentiation is by inference rather than by naming a sibling.

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?

Usage is only implied by the verb 'validate' applied to a page's structured data; there is no statement of when to pick this over validate_sitemap, check_entity, or preview_meta. No prerequisites, preconditions, or exclusions are given.

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