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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely useful context beyond them: that the link carries the price, that payment/terms/address live on lookunique.eu, and that 'nothing is bought here'. It does not, however, say what happens on failure (e.g. size out of stock).

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?

Two tight sentences, front-loaded with what the tool produces and closing with the crucial scoping fact that no transaction occurs here. No filler, though the clause about colour/stock could be sharper.

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 read-only link-builder with no output schema, the description adequately conveys that the return value is a URL with an embedded price and that checkout happens elsewhere. However, with 7 parameters at 29% coverage, it leaves substantial input semantics unexplained.

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 only 29% and the description compensates only partially: it touches colour ('suits the design') and size ('in stock') and implies design_id, but says nothing about side, garment, quantity, or print_size, leaving four of seven parameters with no explanatory value anywhere.

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 a specific resource ('the link that opens exactly this shirt on lookunique.eu, ready to order, with its price'), so the agent knows this returns a purchasable URL rather than a shirt rendering or shop metadata. It is distinguishable from show_shirt and shop_info by implication, but it never explicitly contrasts itself with those siblings.

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?

'After checking that the colour suits the design and the size is in stock' implies a pre-condition/workflow context, but there is no explicit when-to-use, when-not, or named alternative among the siblings (e.g. shop_info). Usage is inferable rather than stated.

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