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

Annotations already declare readOnlyHint, openWorldHint and non-destructive behavior, so the safety profile is covered. The description adds real behavioral context beyond that: results are ordered closest race first, each seat carries a page URL, and prices are never estimated — an unpriced seat returns null. The null-vs-estimate guarantee is exactly the kind of disclosure that prevents an agent from misreading a missing value.

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 sentences, both front-loaded: the first is the retrieval trigger, the second is the payload. Every clause (holder, rating, forecaster bands, price, sort order, URL, null policy) earns its place with no filler.

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?

With no parameters, no output schema and full annotation coverage, the description's only remaining job is describing the returned data, which it does field by field, including sort order and the null-pricing edge case. Nothing needed to invoke or interpret the result is missing.

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?

The tool takes zero parameters, so the baseline of 4 applies: there is no parameter syntax for the description to clarify, and the schema is trivially complete. The description correctly spends no words on inputs.

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 resource (every 2026 Senate seat) and enumerates exactly what each entry contains: holder and role, structure rating, forecaster bands, live Kalshi price, page URL. The scope ('every seat') is unambiguous and the Senate focus distinguishes it from the broader siblings like race_odds.

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?

Gives explicit trigger phrasing: 'Use for "2026 Senate map" and "which Senate seats are toss-ups"', which tells the agent the question shapes this tool answers. It stops short of naming an alternative (e.g., race_odds) or a condition where this tool is the wrong choice, so it is clear context rather than full when/when-not guidance.

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