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

Annotations provide readOnlyHint=true, and the description adds meaningful behavioral context beyond that: the data source (FEC Schedule E), the scope (independent spending to support or oppose), and that it returns totals. It does not mention pagination, response shape, or rate limits, but for a read-only data lookup with strong source disclosure, this is solid.

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?

The description is compact and front-loaded: the first sentence defines the tool precisely, the second provides illustrative queries, and the final tip is short and useful. Every sentence earns its place with no redundant wording.

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?

Given the tool's simplicity, three well-documented parameters, and no output schema, the description covers the essential context: what counts as outside money, what is returned, and example natural-language queries. It omits details like whether support and opposition totals are shown separately, but the phrase 'support or oppose' and the limit parameter's 'per side' description cover the main gaps.

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 100%, so the baseline is 3; the description adds a modest reminder that candidate names go in as written, which complements the schema examples. It does not add substantive meaning to the cycle or limit parameters beyond their existing schema descriptions, so no higher score is warranted.

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 action with a clear resource: it lists every super PAC and other filer spending independently to support or oppose a candidate, with totals from FEC Schedule E. It is unambiguously per-candidate and independent-spending oriented, which distinguishes it from sibling tools like pac_totals or super_pacs. The example queries reinforce what the tool answers.

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 provides clear context through example questions such as 'who is backing Trump' and 'which groups are attacking this senator', implying when to use the tool. It does not explicitly name alternative tools or state when not to use it, so it stops short of a 5. The note 'Candidate names go in as written' also gives practical input guidance.

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