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

The readOnlyHint annotation already establishes that this is a safe read operation, so the description does not need to cover safety. It adds that the templates are built-in and filterable, but does not describe output shape, pagination, or whether all built-in templates are returned by default.

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 a single front-loaded fragment with no wasted words, and the core resource plus optional filter are stated immediately. Its fragment style is efficient but slightly less explicit than a complete sentence naming the list action.

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 simple read-only list tool with one optional filter and no output schema, the description covers the essential purpose and filtering behavior. It leaves minor gaps around return format and category semantics, but nothing critical for selecting or invoking the 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?

Schema description coverage is 0%, so the description does help by explaining that the single 'category' parameter is an optional filter. It still does not clarify valid category values, whether matching is exact, or what happens if an unknown category is supplied.

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 built-in/system habit templates and gives examples (water, steps, sleep), distinguishing it from user-created or master habit tools. The listing verb is only implicit rather than stated, which keeps it from being fully precise.

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?

It implies the use case ('a coach can start from') and notes that category filtering is optional, giving some context. However, it does not state when to choose this over siblings such as master_habits, list_client_habits, or create_habit, and offers no exclusions.

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