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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, yet the description still adds real value: no account/upload/launch side effects, no credit cost ('MCP tool calls use no Adrails credits'), and the absence of an embedded card with the note to surface a browser approval link. It stops short of failure modes or fetch limits, keeping it at 4.

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?

Purpose and return payload are front-loaded, and nearly every clause carries actionable detail. It is dense and slightly over-packed with semicolon-chained clauses, and 'Read only' partly restates the readOnlyHint annotation.

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 does the heavy lifting by enumerating the returned fields and the launch_brief values it settles. Only minor gaps remain — how failures or non-Shopify sites are handled — which an agent can tolerate given the read-only annotations.

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 75%, so the schema already documents url, accountIds, userStatement and idempotencyKey. The description reinforces url implicitly and adds useful context on userStatement (verbatim, required for launch_brief), but says nothing about accountIds scoping or idempotencyKey — baseline 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?

States a specific verb and resource ('Reads a public website or store') and enumerates exactly what it returns: brand, product list, language, currency, prices, links. It is clearly distinguishable from sibling store_products, which covers connected-store data rather than a public page scrape, and it names the downstream consumer (launch_brief).

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?

Gives an explicit trigger ('when its contents are needed for the requested ads') and explicit exclusions: it 'does not infer the account, budget, countries, dates, Page or pixel; reuse those from the request and saved brief.' It also routes the agent elsewhere for open questions via launch_brief with userStatement passed verbatim.

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