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 useful behavioral context beyond that: it discloses the returned fields (URLs, contact details, hours, jurisdictions) and a genuine caveat that 'addresses may be outside the selected service region', warning that results may not strictly match the filter.

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?

Three tightly written sentences with the core action front-loaded, followed by return contents, a caveat, and the routing hint. No sentence is redundant and every clause earns its place.

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 an output schema present, return-value details need not be enumerated, and annotations carry the safety profile. The description still supplies the source of the parameters, the follow-up tool, and the important out-of-region address caveat, leaving nothing an agent needs in order to call it correctly.

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%, so the country and region parameters are already fully documented with their allowed values. The description reinforces that both are required and sourced from bbb_regions but adds no syntax or format detail beyond what the schema provides; baseline 3 is appropriate.

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 opens with a specific verb and resource ('List BBB chapters and public primary/branch offices') and scopes it to a required country and region. It explicitly ties the resource to its source ('from bbb_regions') and names the follow-up tool (bbb_local_bbb), so an agent can distinguish it from siblings like bbb_local_bbb and bbb_regions without opening a 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?

It states the prerequisite for the region parameter ('from bbb_regions') and routes the agent onward with 'Use a returned chapter URL with bbb_local_bbb', naming the alternative tool and the condition that selects it. The workflow context is explicit rather than implied.

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