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

Annotations declare readOnlyHint=true and openWorldHint=false; the description is consistent and adds valuable context beyond annotations: the score scale (0-100), acceleration/deceleration thresholds, the reference period ('last three lag-safe months vs prior same-type cycle'), the returned fields, and the weekly update cadence. This goes beyond simple 'returns a score' and helps set expectations.

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 dense but every clause earns its place: it defines the metric, scope, time window, thresholds, output fields, usage triggers, and update frequency. No filler or repetition; the key information is front-loaded in the first sentence.

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?

The description covers the return fields, meaning of the score, coverage scope, and update frequency, which is quite complete for a read-only snapshot tool. It lacks discuss of error conditions or edge cases (e.g., missing FEC data), but the optional days parameter is fully handled by the schema, so the overall context is solid.

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% for the only parameter ('days'), so the schema fully documents it. The main description adds nothing about the parameter, but with complete schema coverage, the baseline of 3 is appropriate; the description does not need to compensate for gaps that do not exist.

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 uses a specific verb ('Returns') and a highly specific resource ('a 0-100 US federal political-money velocity score') with detailed scope (contributions and spending across FEC-registered candidate, PAC, and party committees). It also explains the score's meaning with thresholds and lists output fields, making the tool's purpose unmistakable and distinct from any sibling.

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?

Explicit when-to-use guidance is provided: 'Call when the user asks how fast campaign money is moving, about fundraising or PAC spending pace, or when timing political-ad inventory or government-affairs budgets.' It does not list alternatives or when-not-to-use cases, but the guidance is clear and actionable for the target scenarios.

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