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

Annotations already show readOnlyHint=false and destructiveHint=false, so the description carries a lighter burden. It adds valuable context beyond annotations by specifying that the tool flips a boolean and that paused entries stop generating reminders/occurrences until resumed. This is exactly the kind of behavioral disclosure that annotations don't capture.

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, well-structured sentence that front-loads the action, names the resource, explains the mechanism, and states the behavioral consequence. Zero filler words—every clause earns its place.

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 only one parameter, no nested objects, an output schema present, and annotations covering safety, the description provides everything an agent needs to invoke the tool correctly. It explains the effect on future occurrences and implies recoverability, making it complete for this simple 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 100% for the single parameter, and the schema description ('From list_scheduled_workouts.') already tells the agent where to obtain the ID. The tool description adds no additional parameter-specific insight, so the baseline of 3 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 description states a specific action ('Pause or resume') on a specific resource ('scheduled-workout entry') and even explains the underlying mechanism ('flips is_active'). This clearly distinguishes it from siblings like create, update, or delete scheduled workout, which have different purposes.

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 makes it obvious when to use this tool: when you want to pause or resume a scheduled workout. It explains the effect (reminders/occurrences stop) and implies reversibility. However, it does not explicitly name alternatives or exclusion criteria, such as 'use update-scheduled-workout-tool for changing other fields,' so it just misses a 5.

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