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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds useful context by naming exactly which fields come back and which endpoint backs it, but says nothing about auth requirements, error behavior for unknown ids, or latency/rate limits.

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?

Very short and front-loads the resource and the return payload before the endpoint. The telegraphic fragment style ('One of your CustomCat products by id') costs a little readability, but no sentence is wasted.

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?

A one-parameter read-only lookup needs little more than this; annotations cover the safety profile and the description enumerates returned fields in lieu of an output schema. Minor gap: no mention of failure mode when the id doesn't exist or belongs to another account.

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% with a single required product_id, and the description's example id (22-2580581) merely repeats the schema's own example. Baseline 3 applies since the schema does the heavy lifting and the description adds no validation or format nuance beyond 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?

Names a specific verb+resource (fetch a single product by id) and enumerates the returned payload — variants, SKUs, cost, price, options, designs — plus the endpoint. It implicitly distinguishes 'your' products from catalog products via the sibling set, but never explicitly contrasts with customcat_get_catalog_product or customcat_list_products, and the verb is elided in favor of a noun fragment.

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?

No statement about when to use this versus list_products (browse) or get_catalog_product (catalog lookup). The only hints are 'by id' and 'your', leaving the agent to infer the selection conditions from the name.

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