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

The description goes well beyond the annotations by disclosing that it performs no model call, network lookup, payment, or target-tool execution, and never returns supplied secret values. This gives the agent a precise safety and side-effect profile that annotations alone do not convey.

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?

Two tight, front-loaded sentences convey the tool's role, invocation pattern, output shape, and behavioral guarantees without redundant or vague filler. Every sentence earns its place.

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?

The description, combined with the output schema and annotations, gives the agent enough to select and call the tool correctly: what it does, what filters it accepts, what it returns (one to three tools with exact prices, required inputs, and a safe workflow), and what side effects it avoids. The short output schema also removes the need to document return fields in prose.

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 only 13%, so the description must compensate, and it does partially by naming category, country, chain, price cap, and available input names. It also adds the important semantic rule that available input names are supplied without their values, though max_results and prefer_free are only implied rather than explicitly described.

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-resource relationship: it is a deterministic router over the published Agent Card that returns one to three matching tools. It clearly differentiates itself from the many sibling tools by describing its meta-selection role rather than a domain-specific operation.

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 description gives clear invocation context: describe the job and optional category, country, chain, price cap, and available input names. It does not name explicit alternatives or state when not to use it, but its router-over-Agent-Card framing makes the intended triggering condition reasonably clear.

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