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

Annotations already declare readOnly/openWorld/non-destructive, so the safety profile is covered. The description adds genuinely new behavior: prices are never estimated, unpriced seats return null, results are sorted closest race first, and no key is required. That is meaningful context beyond the annotations, though return pagination or rate limits are unmentioned.

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 trigger phrases, then a compact enumeration of returned fields, the null-pricing rule, sort order, and free/no-key status. Every clause carries information; 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 output schema, the description carries the burden of explaining return shape, and it does: field list, closest-race-first ordering, null for unpriced seats, and per-seat URLs. An agent has everything needed to call and interpret the result.

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 there is nothing for the description to disambiguate and the baseline of 4 applies. No parameter-level guidance is needed or missing.

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 (2026 Senate map, every seat) and enumerates exactly what each seat carries: holder/role, structure rating, forecaster bands, live Kalshi price, and a per-seat page URL. It is immediately distinguishable from adjacent tools like race_odds by being a full-map enumeration rather than an odds lookup.

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 phrases ("2026 Senate map", "which Senate seats are toss-ups") that map intent to tool cleanly. It stops short of naming an alternative or exclusion (e.g., when to prefer race_odds for a single market), so it is clear context without routing rules.

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