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

Beyond the readOnly and openWorld annotations, the description discloses important behavioral details: results are newest first, a total count is included, the legal restriction on contributor names is stated, and pricing/failure-charging behavior is specified. These are meaningful operational traits not available from the structured fields alone.

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 front-loaded with the core purpose and data scope, followed by legal and pricing details that are relevant to correct use. It is dense and includes a long return-field list, but nearly every clause adds useful context.

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 output schema, annotations, and 100% parameter description coverage, the description is complete enough for an agent to invoke the tool correctly. It also adds return ordering, total count, legal restrictions, and payment details that round out operational understanding.

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 all seven parameters are already documented in the input schema. The description reinforces the query dimensions and cycle semantics but does not add significant syntax or format detail beyond the schema examples, so the baseline of 3 is appropriate.

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 dataset and retrieval scope: US federal campaign contributions from FEC Schedule A itemized receipts, queryable by contributor name, employer, committee ID, or state for a two-year cycle. It also lists returned fields and ordering, making the tool's purpose immediately clear and distinguishable from unrelated finance siblings.

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 clearly establishes the retrieval context by listing the supported query dimensions and the two-year cycle scope, which gives an agent enough to know when this tool applies. It does not explicitly name when-not-to-use or alternatives, but no close sibling tool performs the same campaign-finance lookup.

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