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

Annotations already declare readOnlyHint and idempotentHint, yet the description still adds substantive context: required OAuth scope store:read, the prerequisite of an approved store, the error behavior when no approved store exists, and the zero-count result for an empty store. The 'no quantities are reserved or changed' line reinforces the non-destructive profile with a concrete guarantee.

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?

Front-loaded with purpose and scope, then prerequisites, then return shape, then edge-case behavior — a logical progression with no filler sentences. Every clause carries either routing, auth, or result information.

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?

There is no output schema, and the description compensates by enumerating the returned fields (counts by listing status, totalListings, totalQuantity, totalQuantityAvailable). Combined with auth prerequisites and error/empty-state behavior, an agent has everything needed to call it and interpret the response.

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?

Zero parameters, so the baseline is 4; the description correctly confirms 'no arguments are needed', preventing an agent from hunting for inputs. Nothing further is required or possible here.

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 ('Summarize the connected seller's store inventory') and immediately scopes it as an aggregate rather than listing-level view. The contrast with 'individual listing details' lets an agent separate it from siblings like supercatch_list_store_listings without opening either schema.

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?

Explicit when-to-use ('aggregate stock overview') plus explicit exclusions ('per-card prices, sales orders and stock adjustments are outside this summary'), which routes the agent to the pricing, order, and adjustment tools. It does not name those siblings literally, but the functional boundaries are unambiguous.

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