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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered; the description adds the returned fields and the downstream failure consequence of a bad SKU. It says nothing about what happens when the id itself is invalid or unknown (error vs. empty result), which is the one behavioral gap.

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?

Three short sentences, front-loaded with the result shape then the usage rule. The raw endpoint string is minor weight but does convey the REST path, so it mostly earns its place.

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 one-parameter read tool with no output schema, the description adequately states what is returned (price, stock status) and why it matters. Only the error/not-found behavior is left unstated.

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 is documented with a numeric example, so the description needn't repeat it. The endpoint template hints the id is a path segment but adds no semantics beyond the schema — baseline 3.

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?

"One catalog SKU with its price and stock status" names a specific resource and the exact payload, separating it from list_catalog and the product-level tools. It does not explicitly distinguish itself from customcat_get_catalog_product or customcat_get_product, leaving the SKU-vs-product boundary to be inferred from the name.

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?

"Use it before ordering" gives an explicit trigger and the rationale (out-of-stock, discontinued or invalid SKUs make the order fail). It does not name customcat_create_order as the sibling it pairs with, but the context makes the workflow unambiguous.

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