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

The readOnlyHint annotation already establishes that this is a safe read, so the description carries a lighter burden, yet it adds nothing about what a stall record contains or how an unknown stall is handled. "Price: free" is opaque — it could mean the tool costs no quota or that a returned field is priced at zero — and this ambiguity actively risks misreading the result.

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?

The definition is short and front-loaded, but brevity here is under-specification rather than economy. The second sentence, "Price: free," spends space on an ambiguous fragment instead of on identifier format or usage guidance.

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?

This is a simple one-parameter read tool with no output schema and readOnlyHint set, so expectations are modest, but the total absence of parameter format guidance leaves the agent unable to construct a valid call without guessing. Given the cryptic "Price: free" line, the definition is not complete enough to invoke confidently.

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?

With schema description coverage at 0% and one required parameter, the description must explain what "stall" accepts, but it never says whether it is an ID, slug, or display name, nor whether it is case-sensitive. The phrase "One stall's listing" only weakly implies the parameter identifies a stall, adding no usable format information.

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?

"One stall's listing" names a single specific resource, which implicitly contrasts with a listing-style sibling like bazaar_list, but there is no verb and "listing" is ambiguous (a description of the stall vs. an item posted by the stall). An agent can guess this is a detail fetch for one stall, but the purpose is inferred rather than stated.

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 description gives no when-to-use guidance, no prerequisites, and never names the sibling that lists stalls or the parallel niche_detail tool. The only hint is the word "One" in contrast to a plural list, which the agent must supply itself.

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