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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuine behavior beyond that: what each mode actually does (generate produces JSON-LD, validate checks it, product_page inspects an existing ecommerce page for price/stock/merchant fields) and the required input per mode.

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?

Front-loads the one-line purpose, then uses a compact mode = behavior = requirement structure that is easy to scan. Dense but every fragment carries routing or prerequisite information; only the type enumeration is slightly list-heavy.

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 six-parameter, three-mode tool with an output schema and full annotation coverage, the description covers what each mode does and what each needs, so an agent has enough to call it. It leaves the memory_key side effect and the detail parameter's impact largely to the schema, a minor gap.

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 the baseline is 3, but the description goes further by tying parameters together across the mode enum: url is needed for generate and product_page, jsonld for validate, and the type enum is spelled out with a note that 'auto' is the default. That cross-parameter conditional logic is not expressible in the flat schema and adds real value.

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?

States a specific resource (JSON-LD structured data for rich results) and then decomposes the tool into three concrete operations: generate, validate, and product_page. Each mode is described with its own verb and required input, so an agent can tell exactly what the tool produces in each case.

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?

Explicitly gives per-mode selection guidance and prerequisites ('Needs url', 'Needs jsonld') and disambiguates an easy mistake by routing Product writing to 'generate with type Product'. It does not name any sibling alternative or state when not to use the tool, so it stops short of a full when-to-use/when-not treatment.

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