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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds the returned field set (spender, amount, date, support/oppose, description), which is useful behavioral context, but says nothing about pagination, result ordering, or completeness limits beyond the schema's limit param.

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, no filler: the first defines scope and returned content, the second front-loads the required-input constraint. Nothing redundant.

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 usefully enumerates the fields returned and states the input requirement, and annotations carry the safety profile. Minor gap: no note on result volume/ordering behavior for a list endpoint.

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%, and the schema already documents cycle, limit, candidate_id, and committee_id with examples and defaults. The description's 'Provide candidate_id or committee_id' merely restates the schema's own constraint, adding no syntax or format detail beyond it.

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 ('List') and resource ('independent expenditures'), plus the FEC Schedule E provenance and the directionality (supporting/opposing a candidate or made by a committee). Clear enough to distinguish from generic search tools, though it does not name a sibling like fec_candidate_financials to sharpen the boundary.

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 closing sentence 'Provide candidate_id or committee_id' gives a real usage constraint, implicitly ruling out parameterless calls. However it offers no when-to-use-vs-alternative guidance relative to the other FEC tools (candidate financials, committee search).

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