get_habits

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

The readOnlyHint already tells the agent this is a safe read operation, but the description adds meaningful behavioral context: it includes former habits as well as current ones and explains why past exposure matters for risk. It also specifies the expected tone for presenting habits, though it does not describe empty states, ordering, or other retrieval mechanics.

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 reasonably compact and front-loads the resource and returned fields. It includes some extra clinical-presentation guidance ('state them as facts, without moralising') that is useful for a health assistant but slightly beyond bare tool-selection content.

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?

Given the zero-parameter schema, read-only annotation, and available output schema, the description covers the important gaps: scope of habits, inclusion of former habits, relevant fields, clinical relevance, and sibling routing for add/update. Nothing essential for correct invocation 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?

The tool has zero input parameters, so the schema needs no parameter explanation and the baseline score is 4. The description adds output-field detail, but because there are no input parameters and an output schema exists, it does not need to do more for parameter semantics.

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 identifies the resource as user-reported habits (smoking, alcohol, cannabis, vaping, and similar) and enumerates the returned fields such as habit_type, status, frequency, and optional quantities. It also distinguishes this retrieval tool from the mutating siblings record_habit and update_habit at the end, so an agent can tell exactly what this tool is for.

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 explicitly routes add and change operations to record_habit and update_habit, which is strong alternative guidance. It also gives clinical context for using the returned data, but it does not spell out a when-not-to-use condition or a full decision rule for when get_habits itself should be selected.

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