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

With no annotations, the description carries the full disclosure burden. It does add two pieces of real behavioral context beyond the schema: the plan gating ('Requires Pro / Max') and the breadth of the payload (six metric families). It omits, however, what a response looks like, whether both parameters can be combined, and what happens if neither is supplied — notable for a 0-required-param tool.

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 dense sentence that front-loads the verb and the resource, then lists the metrics in a compact parenthetical, closing with the plan requirement. Nothing is wasted and the ordering is sensible.

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 two-parameter, optional-only lookup with a fully documented schema and no output schema, this is close to sufficient: purpose, metric inventory and access tier are all present. The remaining gap is the interaction between search and categorySlug and the default behavior when neither is given.

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 both parameters are well documented in-schema, including the English/Chinese keyword behavior and slug examples. The description adds no parameter-level meaning beyond that, so the baseline of 3 applies.

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?

Specific verb and resource: 'Query pricing benchmarks and market distributions across 249 niches', followed by an enumerated list of the exact metrics returned (median entry price, top-tier price, free/trial share, bucket distribution, traffic concentration, sample prices). The scope (249 niches) and the family of metrics make it distinguishable from siblings like get_market_pulse or get_evaluation at a glance.

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 intended downstream use ('to build high-converting Pricing pages'), which implies when to reach for it, and 'Requires Pro / Max' flags an access gate. But there is no explicit when-not guidance, no mention of when to use search versus categorySlug, and no named alternative for pricing comparisons (e.g. compare_products).

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