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

Annotations already declare readOnlyHint and openWorldHint, and the description adds genuinely new context: a per-call cost of $0.005 USDC via x402, which is critical for an agent deciding whether to invoke it. It also enumerates the returned fields, though it says nothing about rate limits, result caps, or failure behavior when no match is found.

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?

A single dense sentence that front-loads the data source and enumerates outputs, followed by the cost disclosure. No filler, though the field enumeration makes the sentence long and slightly list-like.

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 carries the return-value burden and does so by enumerating the fields and links returned. Cost is disclosed, which matters for a paid x402 endpoint; only the meaning of the cycle parameter and result limits are left unstated.

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 both parameters (q, cycle) are already documented in the schema and the baseline is 3. The description reinforces the name-matching intent of q but adds no semantics for cycle beyond the schema's 'Election year, e.g. 2026'.

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 names a specific domain and resource (US campaign finance from the FEC) and spells out exactly what is returned: candidates and committees matching a name, with party, office, state, status and latest totals. An agent can tell it retrieves FEC entity data, though it never distinguishes itself from adjacent siblings like congress or filings.

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?

There is no explicit when-to-use guidance, no prerequisites, and no mention of alternatives such as congress for legislators or sec_search/filings for other financial disclosures. The agent is left to infer that this tool covers campaign-finance lookups only from the resource name.

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