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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the returned facets, but says nothing about behavior on an invalid/unknown code, an out-of-market code, or how the optional lat/long affect the call. With annotations carrying most of the burden, a 3 is appropriate.

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?

A single front-loaded fragment with zero filler; the scoping detail ('by code') appears first and the returned fields are listed compactly. Slightly terse as a full sentence, but nothing is wasted.

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 single-record lookup with a full output schema, full parameter descriptions, and safety annotations, the description covers the essentials. The only real gap is routing guidance to/from the sibling search tool.

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 the schema already documents code, market, latitude and longitude (including defaults and the SG-only enum list). The description adds no parameter meaning beyond that, so baseline 3 applies.

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+resource ('darkstore detail by code') and enumerates the returned facets (address, coordinates, chain, budget tier, delivery/pickup availability). This distinguishes it from the store_products/store_search siblings, though it doesn't name an alternative explicitly.

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 'by code' phrasing implies a prerequisite identifier but gives no when-to-use guidance, no mention of the sibling that produces the code (pandamart_search), and no when-not-to-use conditions. An agent must infer routing entirely from sibling names.

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