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

Annotations already establish readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds important behavioral context: limited free results, paid upgrade links, x402 payment via Apify, no Apify account needed, and concrete free-tier limits per IP/ASN/global day.

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 definition is front-loaded with the core return value, then usage exclusions and quota details. It is compact and mostly wastes no space, though the free-limit wording is dense and slightly ambiguous.

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 simple one-parameter embedding tool with no output schema, the description covers purpose, scope, payment behavior, and rate limits. It does not specify vector dimensions or exact return shape, but the core invocation requirements are adequately covered.

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% for the single parameter, and the schema already says it accepts "One text or HTML fragment." The description reinforces single-text usage but does not add parameter semantics beyond the schema.

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 states a specific verb and resource: it returns one text embedding vector. It also explicitly scopes the tool to a single text and rules out batch work, making it distinguishable from sibling text-processing tools.

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?

It gives clear usage guidance: "Use for one text" and "Not for batch work or unrestricted monitoring." It does not name a specific sibling alternative for batch work, but the exclusions are explicit and actionable.

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