list_habits

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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds real behavioral value by revealing that only active habits are returned and which derived metrics (streak, hit rate, last miss reason) come back, but says nothing about ordering, pagination, or how staleness is computed.

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?

One dense fragment covers scope plus four distinct outputs with no filler. It is front-loaded on scope, though the missing leading verb makes it read as a field list rather than a task statement.

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 it names the key fields — which is the minimum needed. It leaves open whether inactive/archived habits exist, the ordering of results, and the definition of 'this period', so an agent cannot fully predict the response.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a no-parameter tool applies.

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 fragment 'Active habits with this period's count vs required, streak, recent hit rate and last miss reason' tells an agent this lists habits and what metrics accompany them, but there is no verb or framing sentence, and it never contrasts with siblings like get_context or weekly_review which may surface similar data.

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?

No statement of when to call this versus log_habit, create_habit, list_goals, or weekly_review. The only implied guidance is 'active' and 'this period', which is scope, not usage instruction.

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