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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, covering safety and idempotency. The description adds valuable behavioral context beyond this: it clarifies the output is a ranking from a distributor snapshot and explicitly states it is not a live quote, which alerts the agent to potential staleness. It also implies the result is a relative comparison, not absolute figures. No contradiction with annotations.

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?

The description is a single, well-structured sentence that front-loads the core output aspects (price tier, stock posture, library class) and then adds the crucial context about being a snapshot ranking. Every phrase earns its place; there is no filler or redundancy.

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?

Given the presence of an output schema, the description need not explain return values. Annotations cover safety and idempotency, and the schema covers parameter requirements. The description effectively conveys the tool's purpose and the nature of its data (snapshot vs. live). The only gap is explicit usage guidance, but that is already accounted for in the usage_guidelines dimension. For its complexity, this is nearly complete.

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?

The input schema has 100% description coverage; the schema already explains the 'parts' parameter, including the requirement for two or more parts and the condition of needing at least two priced parts for a verdict. The description adds no additional meaning about the parameter itself, only restating 'a set of IC part numbers.' With full schema coverage, the baseline of 3 is appropriate.

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 clearly states the tool's function: it provides relative price tier, stock posture, and library class for IC part numbers. It specifies the resource (IC parts) and the distinct output dimensions, and the parenthetical clarifies it's a snapshot ranking rather than a live quote. This distinguishes it from typical lookup or search tools and sets clear expectations.

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?

The description implies usage for comparing parts using distributor snapshot data, but it never explicitly states when to use this tool over its siblings (find_parts, search, lookup, etc.) or provides any exclusion conditions. The only hint is the 'not a live quote' caveat, which is more about data nature than usage context. There is no mention of alternatives or when-not-to-use.

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