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

The annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the description only needs additive context — and it delivers that by describing the return payload (source product plus same-category Buying Club items with TrustScore, price, member price, cashback), which matters since there is no output schema.

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?

Two sentences, zero waste: the usage trigger is front-loaded and the return content follows. Nothing is padded or repeated from structured fields.

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 read-only comparison tool with rich annotations and no output schema, the description supplies the trigger plus the return shape an agent needs. Minor gaps (no pagination/limit behavior, no explicit sibling routing) keep it from full marks.

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%, so all six parameters are self-documented and the baseline is 3. The description adds no syntax or filtering semantics beyond hinting product_id_or_slug is usually an existing user product.

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 (compare) and resource (Buying Club) scoped to 'a specific product.' It is clear, but it never names or distinguishes itself from the close sibling suppco_compare_product_to_alternatives, so an agent cannot fully disambiguate the two from the description alone.

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?

'Use this when the user asks whether the SuppCo Buying Club carries an alternative to a specific product' gives explicit trigger conditions and even notes the typical input ('usually one they already take'). It stops short of exclusions or naming the alternative tool (compare_product_to_alternatives) that handles non-Buying-Club comparisons.

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