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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond the annotations: the exact fields returned (memory, bandwidth, memory type, release year, status, dated price), the meaning of a null price, and a negative scope boundary. It doesn't cover cardinality edge cases or ordering of results, but it is well above the annotation baseline.

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?

Four tight sentences with no padding; the usage trigger and prerequisite are front-loaded, followed by return fields and the scope exclusion. Slight redundancy between the first sentence's 'two to four machines' and the schema, but it earns its place as a routing cue.

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?

An output schema exists, so return-value explanation is optional, yet the description still names the compared fields and the null-price convention, which is a useful addition. Combined with annotations covering safety and the schema covering parameter constraints, the definition is complete for correct invocation; only minor details like result ordering are absent.

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% and the schema itself documents the 2-4 cardinality and the pattern via constraints. The description repeats the 'two to four hardware ids from search_catalog' framing already in the schema description, so it adds no syntax or format meaning beyond what structured fields provide. Baseline 3 is correct.

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 (compare) and resource (machines), specifies the 2-4 cardinality, and explicitly distinguishes itself from the sibling check_hardware_fit by stating 'It does not check any model against the machines'. An agent can route between the two tools without opening either schema.

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 gives a clear when-to-use trigger ('when the user compares two to four machines'), a prerequisite (hardware ids from search_catalog), and names the alternative tool (check_hardware_fit) with the condition that selects it. All the routing information an agent needs is present.

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