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

No annotations are provided, so the description carries the full disclosure burden. It implies a read-only listing and states that results are scoped to the authenticated user, but says nothing about pagination, result volume, ordering, auth failure behavior, or what a merchant record with heatmap coordinates contains — all material for a list endpoint with zero annotation coverage.

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 sentence with no filler; the scope-defining phrases come in the right order. The parenthetical "(heatmap)" is slightly cryptic but compact enough not to be wasteful.

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?

With no annotations and no output schema, the description should explain what the listing yields and how it behaves, but it only names the resource. It is adequate to identify the tool but leaves an agent without enough to predict the response shape or scale for a data-returning list operation.

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 coverage is 100% and the single bearerToken parameter is fully documented in the schema, so baseline 3 applies. The description's phrase "for the authenticated user" loosely contextualizes the optional token but adds no format, precedence, or fallback detail beyond what the schema already states.

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?

The description gives a specific verb and resource ("List merchants") plus the data scope ("location data (heatmap)") and ownership scope ("authenticated user"), which distinguishes it from the singular get_merchant_metadata sibling by name convention. It never explicitly states the relationship to get_merchant_metadata, so differentiation is inferred rather than declared.

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?

There is no when-to-use or when-not-to-use guidance, and no sibling is named as an alternative. The agent must infer that this is the multi-merchant, location-oriented listing versus the single-merchant lookup based on the verb alone.

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