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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety needs no restatement. The description adds real value beyond them by disclosing the return payload's scope in detail, which matters because there is no output schema. It says nothing about what happens when an id is unknown (openWorldHint=false suggests closed-world), so a small gap remains.

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 the action and scope stated first, followed by a tight enumeration of return fields. Every clause carries information, though the long comma-list would read more scannably if broken out; no filler is present.

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 single-parameter read tool with no output schema, the description supplies precisely what structured fields cannot: the full contents of the response an agent will receive. Combined with annotations covering the safety profile, nothing essential to correct invocation is missing.

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 parameter already carries the description "Product id from search_products", which the tool description merely echoes. Baseline 3 applies: the schema does the heavy lifting and the description adds no format, range, or edge-case meaning on top of it.

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 verb and resource ("Get full details of one shop product by its id") and then enumerates exactly what is returned: description, variants with prices and stock, shipping zones and costs, delivery time, payment methods, pickup, and purchase URL. That distinguishes it clearly from list-style siblings such as search_products and get_catalog_overview.

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 parenthetical "(from search_products)" makes the intended call sequence explicit, which is the key usage guidance for a lookup-by-id tool. It stops short of naming alternatives or exclusions — notably it never says how this differs from get_offer — so the agent must infer the product-vs-offer boundary.

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