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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds the return composition (date, goal, streak, tasks), which is useful since no output schema exists, but it omits any behavioral notes like aggregation or refresh semantics.

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?

A single tight sentence that front-loads the resource and lists the payload without filler. Every clause earns its place, including the sibling pointer.

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 must explain returns, and it does enumerate the fields an agent receives. Combined with read-only annotations, this is nearly complete, though it could clarify whether the result is a single aggregate snapshot vs. a list.

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 schema takes zero parameters, so there is nothing to clarify and the baseline of 4 applies. No syntax or format ambiguity exists for the agent to resolve.

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 names a clear resource (the user's 'today') and enumerates the specific payload: time-zone date, main goal, day streak, and today's tasks. It partially distinguishes itself from the sibling get_tasks by noting shared tasks are covered there, though it doesn't state a verb explicitly.

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 pointer 'shared ones too, see get_tasks' implies a routing relationship to a sibling, but it doesn't state when to prefer this tool over get_tasks or get_habit, nor any exclusion conditions. Usage is only loosely implied.

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