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

The description adds behavioral context beyond annotations: filtering of expired countdowns and inactive streaks, plus OAuth/scoped credential requirements and per-call cost. These complement the readOnlyHint and idempotentHint annotations without contradicting them.

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?

Two dense sentences with no wasted words. The core scope ('Authenticated user live trackers only') is front-loaded, and the auth/cost details are efficiently appended.

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?

For a zero-parameter read tool with an output schema and annotations, the description covers the essential selection and invocation context: the exact scope, exclusions, auth, and cost. Slightly minor gaps remain (e.g., no explicit statement of what a 'tracker' encompasses), but nothing required to call it is missing.

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?

This tool has zero parameters, so the schema provides no burden; the baseline for parameter semantics is 4. The description need not explain any parameter details.

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 specifies a clear resource ('Authenticated user live trackers') and states exclusions ('expired countdowns and inactive streaks are omitted'). This distinguishes it from sibling get_* tools by focusing on live habit trackers, though it does not explicitly name an alternative.

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 implies usage for retrieving the authenticated user's current live trackers, and the exclusion of expired/inactive items gives a sense of scope. However, it does not explicitly state when to choose this over other sibling tools like get_people or get_events.

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