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

With no annotations, the description discloses read behavior and default assumptions (Free tier without api_key), adding detail beyond the schema. It does not mention side effects, but the tool appears read-only.

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 two sentences, front-loading the main purpose and adding specific details without unnecessary words. Every sentence earns its place.

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?

Despite no output schema, the description fully explains what the tool returns: plan, limits, monthly usage, handoff limit, and retention period. It also covers the default api_key behavior, making it complete for an account query tool.

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?

The description adds meaning to the api_key parameter by explaining the default behavior when omitted, which goes beyond the schema's description. Given 100% schema coverage, baseline is 3, but the extra context justifies a 4.

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 states the tool queries plan, limits, and monthly usage, specifying 'Handoff monthly limit' and 'retention period'. However, it does not explicitly differentiate from sibling tools like baton_verify_plan, leaving potential ambiguity.

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 provides a prerequisite note about api_key defaulting to Free, but does not explicitly state when to use this tool versus alternatives or include exclusions.

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