Sales by label length for .com, .ai, .io and .co

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered without the prose. The description adds almost nothing behavioral, and its closing claim "Takes no input" is misleading because the input schema exposes an optional `fields` selector — an agent following the prose would never discover that filtering option.

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 scope statement is front-loaded and the usage sentence follows immediately, so the definition is easy to scan at two short sentences. The third fragment "Takes no input" earns no place — it is both redundant and factually wrong about the schema, which is the only real structural flaw.

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?

An output schema exists, so return values need no prose explanation, and the read-only safety profile is carried by annotations. What is missing is any acknowledgment of the `fields` parameter and its accepted keys, leaving the definition incomplete for a tool that does accept an optional input.

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 description coverage is 100% and there is only one optional parameter, so the schema alone documents `fields` adequately and the baseline would be 3. However, the description actively asserts "Takes no input," which contradicts the presence of that parameter and would cause an agent to omit a filter that changes the response shape. That is worse than silence.

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 names the specific measurement (sales by label length) and enumerates the covered TLDs (.com, .ai, .io, .co), so an agent can tell it is a length-based aggregate rather than the word-based sibling. It does not explicitly contrast itself with ud_get_market_sales_word or ud_get_market_sales, leaving that distinction to be inferred from the title and name.

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?

"Use it when someone asks how the length of a name relates to its sale price" gives a concrete triggering question, which is real usage guidance. It stops short of exclusions — nothing says when to prefer the word- or endings-based siblings instead.

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