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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the trailing 'Read-only.' adds nothing and earns no credit. The description does add genuine behavioral context beyond the annotations: that sets done differently from a plan are shown with the planned values beside them, how 'Reviewed by' is determined, and that suggestedNext is the app's own rotation pick when today is unplanned. These affect how an agent should interpret the payload and are real value.

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?

It is a single very long sentence, but the content list is front-loaded and each clause carries distinct information, including the parenthetical about planned values. The parenthetical nesting and the mid-sentence jump to 'suggestedNext' are slightly dense, but little could be cut without losing return-value semantics.

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 burden of explaining return values, and it does so field-group by field-group, including the two non-obvious fields (plan deltas and suggestedNext) and the reviewed flag. It stops short of describing shape, ordering, or how empty states appear, which keeps it from a 5, but it is materially complete for a zero-parameter aggregate read.

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 the schema has nothing to explain and the baseline of 4 applies. The description spends no effort on non-existent inputs and instead uses its space on output meaning, which is the right allocation.

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 enumerates exactly what the tool returns: today's date and weight unit, today's food versus targets, recent workouts, routines, notes, and changes since the assistant's last change. That is a precise, unambiguous picture of an overview snapshot, though it never explicitly contrasts itself with data-returning siblings such as trainrec_recent_changes or trainrec_food_day, which overlap in content.

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?

Usage is only implied: the breadth of the payload suggests it is the first thing to call to get oriented. There is no explicit 'use this before X' or 'use trainrec_recent_changes instead when you only need the diff' guidance, and no prerequisites or exclusions are stated, leaving the agent to infer when the full bundle is preferable to a narrower sibling.

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