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

Annotations only declare readOnlyHint and openWorldHint; the description adds meaningful context beyond them by enumerating the returned fields (rating, accreditation, contact details, totals) and explaining the semantics of `alerts` including the empty-list case. It does not cover pagination or auth, but for a simple read tool this is solid added value.

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 the core action and the input source, then the return overview, then the sibling routing. It is somewhat dense with parentheticals, but each sentence carries distinct information and none 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?

With an output schema present, return values need not be explained, yet the description still maps the key fields and the `alerts` semantics. Combined with the input-source guidance and sibling routing, an agent has everything needed to invoke this 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% and the parameter is documented there, so the baseline is 3. The description adds real nuance: that the URL is required and that `hq_profile_url` should be used for a multi-location business, which the schema only implies by listing both fields.

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 ('Fetch one Better Business Bureau profile') and immediately distinguishes itself from siblings by naming bbb_search as the URL source and bbb_business_complaints as the tool for complaint lists. An agent can tell this apart from neighboring bbb_* tools without opening any 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?

Explicitly routes the agent: get the URL from bbb_search, prefer hq_profile_url for a multi-location business, and use bbb_business_complaints for the complaint list. Both the input source and the alternative tool for a related need are named, leaving little to inference.

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