compare_many

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuine value beyond that: cost ('two requests per group of four terms') and output scaling ('largest average is 100'). However, it discloses no rate-limit ceiling, error behavior, or auth context. Given annotations carry the safety burden, a 3 reflects useful but not rich added context.

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?

Front-loaded with the core purpose, then the rescaling rationale, then anchor, then return/cost. Each paragraph earns its place, though the rescaling explanation runs slightly long for a definition.

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 format needn't be explained (though partially is). But with 0% schema coverage, a 6-parameter tool leaves five parameters wholly undocumented in both schema and description — a real gap for 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 0%, so the description must compensate. It explains 'anchor' well (shared term, blank = auto, mid-sized selection rationale), but leaves geo, category, property, timeframe, and the required keywords format undocumented. It compensates for one of six parameters, so the baseline 3 is appropriate at best.

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 (rank) and resource (6-25 terms) plus the scope that distinguishes it from single-comparison siblings: 'past Google Trends' limit of five per comparison.' The rescaling rationale makes its unique role unmistakable.

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 scope condition (6-25 terms, beyond the five-term limit) clearly cues when to reach for this over the native comparison, and the anchor guidance covers the main decision point. It stops short of naming a specific sibling alternative or exclusion.

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