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

With no annotations, the description carries the full behavioral burden, but for a zero-parameter lookup the surface is small. It usefully discloses the payload shape (ticket average and monthly volume accompany each tier), which partially compensates for the absent output schema, yet it says nothing about auth needs, caching, or whether values are static or computed.

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 resource comes first and the returned fields follow as a compact parenthetical. Nothing could be removed without losing information.

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 simple zero-arg retrieval tool with no output schema, the description supplies the essential missing piece: what each returned tier includes. The remaining gap is context on the domain (business/pricing tiers) and any relationship to calculate_cost, which would help an agent chain calls.

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?

The tool takes zero parameters, so per the baseline there is no parameter semantics to document. The description correctly avoids inventing inputs and instead spends its words on output content.

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 states a specific verb ('Get') and resource ('business tiers') and even enumerates the tier bucket values (MEI, small, medium, large). It is clearly distinguishable in subject matter from the sibling tools (calculate_cost, compare_brands, get_brands), though it never explicitly contrasts itself with them.

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 statement of when to use this tool versus the siblings, no prerequisites, and no exclusions. The agent must infer that this is a reference lookup for tier definitions while get_brands covers brand data.

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