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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, so the safety burden is covered. The description adds real behavioral context beyond them: what is included in the rate (email verification, SMS on paid elections), the optional add-ons, and the guarantee that these are 'the same constants the product bills against,' which tells the agent the numbers are authoritative.

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 core promise ('exact, current pricing') and then lists the components. No filler sentences, though the mid-sentence parentheticals make it slightly heavier than ideal.

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?

There is no output schema, so the description must convey what comes back, and it does: rate, add-ons, promo status, subscription comparison. For a simple read-only pricing tool with a fully documented schema, this is close to complete; only pagination/format details are absent, which are not relevant here.

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 goes further by mapping parameters to meaning: 'flat rate by voter count' explains voters, gov-ID and mailed-letter add-ons explain the two optional integer params, and the subscription clause explains what elections_per_year triggers.

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 verb+resource (exact current pricing for an election) and enumerates the components returned: flat rate by voter count, add-ons, promotional status, subscription comparison. It clearly differs from a general overview tool, though it never explicitly distinguishes itself from the closest sibling, compare_platforms.

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?

Usage is implied rather than stated: an agent can infer this is for pricing a specific election, and the elections_per_year parameter hints at subscription-comparison scenarios. There is no explicit when-to-use/when-not guidance and no named alternative for platform-vs-platform comparison.

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