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

No annotations are provided, so the description carries the full burden. It discloses: it is a read operation ('Light read'), it is cheap ('costs 0.2 credit', 'it is cheap'), what it returns (platform type, catalog readability, currency, product count), and that other tools depend on it. It does not describe rate limits, failure modes, or auth needs, but for a lightweight detection tool the disclosure is strong.

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?

Three tight sentences, front-loaded with what it detects, then when to call it, then cost. Every sentence earns its place — no filler, no repetition of the title.

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?

For a single-param reconnaissance tool with no output schema and no annotations, the description covers purpose, output content (platform, readability, currency, count), cost, and the call-first convention. An agent has enough to call it correctly. Minor gap: no mention of what happens on failure or unreadable stores, but that is a small omission for this tool's complexity.

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 single parameter store_url is thoroughly documented in the schema (accepts homepage, collection page, category page, bare domain). The description adds no parameter detail beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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?

Specific verb+resource: 'detects whether a store runs Shopify or WooCommerce and whether its public catalog can be read', plus returns currency and product count. This is a distinct reconnaissance tool, clearly different from get_product/list_products/search_products. An agent can tell immediately what it does and how it differs from siblings.

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?

'Call it first on an unknown store' gives explicit when-to-use guidance. 'Every other tool needs a readable store' explains the prerequisite relationship with siblings (list_products, get_product, etc.), effectively routing the agent to call this first. Rarely is usage guidance stated this decisively.

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