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

Goes well past the readOnly/idempotent/openWorld annotations by explaining what the data actually is and is not: a listing is an FEC-reported contribution, not a finding about the candidate or any vote; no individual donors are named; PAC money is company-wide, not tied to ICE/CBP work and comes from voluntary contributions rather than treasury or contract funds. That is exactly the interpretive context an agent needs to avoid over-claiming.

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 what the tool returns before filters and caveats, and nearly every sentence carries information. It is one dense, semicolon-chained paragraph with some repetition of schema facts ('as the FEC lists it' appears twice), which costs it the top score.

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 steps in to describe the return shape: committee name plus FEC party, office, state and district, net amount from mapped PACs, per-company split, and total/truncated for the full count. Combined with the caveat block, 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?

Schema coverage is 100%, so parameter documentation is already complete; the description mostly restates it (two-letter state, REP/DEM/other, limit 1-50 default 20, cycle mapping). It adds little beyond the schema, though the 'company name substring among the parents with a mapped PAC' framing clarifies the universe being searched.

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 precise verb and resource: listing federal candidate committees that received contributions from connected PACs of the 100 largest ICE/CBP contractors in the Pay-to-Play Register. The entity is specific enough that an agent can distinguish it from the pay_to_play_totals, pay_to_play_awards and pay_to_play_contractor siblings without opening the schema.

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 clear operational context: one FEC cycle, the 2024/2026 mapping to 2023-24/2025-26 with a stated default, and the four filter dimensions. It never names the sibling tools or says when a caller should prefer totals, awards or contractor lookup instead, so there are no explicit exclusions.

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