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

With no annotations supplied, the description carries the full behavioral burden. It does add one genuinely useful disclosure – prices include VAT – which prevents a downstream miscalculation, and the enumerated return content signals this is a read-only fetch. However, it says nothing about behavior on an unknown or delisted id, response size given 'all images', or whether the card is cached/live.

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?

A single dense sentence, front-loaded with the resource and key, followed by the return payload and one critical caveat (VAT). Nothing is padded and no clause is redundant.

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?

There is no output schema, so the description deliberately compensates by enumerating the fields returned, which is the right call for a card-fetch tool. The lang parameter's behavior is fully delegated to the schema, and only error/delisted-id behavior is left uncovered, which is a minor gap for a read-only lookup.

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%, including a full enum-style list for lang and its domain-based default, so the schema does the heavy lifting. The description adds no meaning about id format (integer, not SKU or slug) or about how lang interacts with the returned description/attribute text. Baseline 3 applies when the schema is this complete.

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 the resource (a full product card) and the lookup key (by id), then enumerates exactly what comes back: description, attributes, colour variants with availability, images, price, GTIN. An agent can distinguish it from get_availability (which only covers availability) or search_products (which returns lists). It stops short of a leading verb and never explicitly contrasts itself with siblings, keeping it at 4 rather than 5.

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 through 'by id' – the agent must infer that this is the follow-up call after search_products or list_categories yields an id. There is no explicit 'use this when you already have an id' statement and no exclusion pointing to get_availability for stock-only questions, even though that sibling overlaps on the variant availability field.

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