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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds meaningful behavior beyond those fields: it is free and needs no key, it can block and require a retry with pasted text, it will not guess missing millimeter dimensions, and it reports missing fields. This gives the agent a clear behavioral model.

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 dense but every sentence earns its place: product scope, cost/auth, call timing, output fields, downstream handoff, error handling, and a guardrail against guessing. It is front-loaded with the most important facts and has no filler.

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, the description carries the burden of explaining return values and does so thoroughly: name, width_mm, depth_mm, height_mm, price, link, blocked, and missing. It also covers input variants and failure recovery. An agent has everything needed to invoke it correctly.

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 schema already describes input as a URL or pasted text. The description enriches this by naming example sources (IKEA, any furniture shop), spelling out the parsed output fields, and clarifying the blocked-and-retry path. It goes beyond the schema without being redundant.

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 names a concrete action ('Turns a product link ... or pasted text ... into real dimensions') and lists the exact output fields. It is clearly distinct from all siblings, which handle rooms, furniture placement, and plans. No ambiguity about what this tool extracts.

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 explicitly says when to call it: 'as soon as the user gives a furniture link.' It also gives a fallback condition ('If blocked is true, ask the user to paste the product page text and call read_product again') and a downstream instruction to pass results into place_furniture. This is strong, actionable usage guidance.

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