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

There are no annotations, so the description bears the full burden, and it delivers very little: no statement that this is a read-only lookup, no pagination or batching behavior, no error semantics for unknown IDs. The only behavioral fact given (the required meta profile) largely restates the schema's required fields and the schema's own description of meta.

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 short sentences, front-loaded with the operation and its accepted keys, with no filler. It loses a point for the garbled/truncated '(g…)' fragment that obscures an identifier form.

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?

With no output schema, no annotations, and nested request objects, the description should say at least minimally what comes back (record shape, unmatched-ID handling). It covers inputs and auth but leaves the entire response contract unspecified, which is a meaningful gap for an agent planning a call.

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%, so the baseline would be 3, but the description adds real meaning by telling the agent what the opaque ids[] array actually accepts — product IDs, variant IDs, catalog numbers, or EANs. That is information the schema description ('lookup_request: ids[] (max 50)') does not convey.

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 states a specific verb and resource (catalog lookup of products) and enumerates the lookup keys (product ID, variant ID, catalog number, EAN), so an agent knows exactly what it retrieves. It does not, however, contrast itself with obvious siblings such as get_product or search_catalog, so 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?

It discloses a prerequisite (meta["ucp-agent"].profile is required) and implies usage via listed identifier types, which is useful context. But it never says when to choose this over search_catalog or get_product, and gives no exclusions, so it stays at implied guidance rather than explicit routing.

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