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

The readOnlyHint annotation already signals a safe read operation, so the description doesn't need to re-establish that. It adds useful behavioral context: contributions are FEC Schedule A based, conduits like ActBlue and WinRed are separated out, and mode changes the interpretation from contributor totals to committee-reported disbursements. No contradiction with annotations exists.

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?

Three sentences carry all the essential information: scope, data source, mode behavior, and routing to super_pacs. There is no filler, no repetition of schema details, and the most decision-relevant facts are front-loaded.

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?

For a read-only tool with no required parameters and a fully self-documented schema, the description covers everything an agent needs to invoke it correctly: ranking basis, election-cycle dimension, conduit handling, mode switch, and the boundary with super_pacs. The return shape is sufficiently implied by 'ranked by total dollars,' and no output schema exists to add further detail.

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 the baseline is 3. The description adds real value beyond the schema by explaining what mode=disbursers actually does and by framing cycle as an election-cycle filter. limit and query are already well described in the schema, so they don't need additional explanation.

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 clearly identifies what the tool does: it lists PAC contributors to tracked candidates ranked by total dollars from FEC Schedule A. It also explicitly differentiates the tool from super_pacs, so an agent can distinguish it from the most similar sibling 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?

It gives explicit usage direction: use for 'which PACs donate the most to Congress' questions, and use super_pacs instead for super PAC questions. It also explains when mode=disbursers should be selected, making the routing guidance actionable.

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