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

Annotations already establish readOnly, idempotent, non-destructive, and non-open-world behavior, so the description only needs to add operational context. It does so usefully: no cost ('Free'), catalog size (242), and the shape of results (service ids, descriptions, prices). It stops short of describing ranking or result ordering.

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 packed sentences, front-loaded with the core action and scout-friendly examples; nothing is redundant or padding.

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 no-output-schema search tool whose safety profile is covered by annotations, the description supplies purpose, cost, scale, and return contents. Minor gaps remain around the 'limit' parameter and result ordering, but nothing blocks correct invocation.

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 50% (query documented as 'Keywords', limit undocumented). The description partially compensates by giving keyword examples that clarify what 'query' accepts, but it says nothing about 'limit', even though the schema caps it at 30. Adequate but incomplete against the coverage gap.

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 ('search') and resource ('Vextorium catalog of 242 paid data services') and pins the search mechanism ('by keywords') with concrete examples. It clearly reads as a discovery tool distinct from a 'call_service' or 'service_details' sibling, though it never names those alternatives explicitly.

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?

The phrase 'Free' implies this is the zero-cost discovery step before the paid call_service sibling, and the keyword examples show expected usage. However, there is no explicit statement of when to use this versus service_details, nor any exclusion or prerequisite guidance.

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