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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds real behavioral context beyond that: default paging values and the notable 'stays nullable (does NOT coalesce to [])' return semantic. It stops short of describing ordering or what a workout entry contains.

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 states the same fact twice — 'start defaults to 0, limit to 100' and then 'Defaults start=0, limit=100' — which is pure redundancy. The content is short but poorly front-loaded, leading with a fragment rather than a clear statement of purpose.

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 two-parameter paginated read tool with annotations covering the safety profile and no output schema, the description covers defaults and the null-vs-empty-array behavior. It is minimum viable but omits result ordering and how the 'library' relates to scheduled or user workouts.

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 schema documents nothing. The description compensates partially by giving defaults for both parameters (start=0, limit=100), but it never explains offset/limit semantics or the effect of large limit values. Adequate but incomplete given the zero-coverage schema.

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 phrase 'a page of the workout library' names the resource and implies a paginated list, but the verb is only implicit and the description is dominated by pagination mechanics rather than stating its purpose. It does not distinguish itself from siblings like get_workout_by_id, get_scheduled_workouts, or get_training_plan_workouts.

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?

There is no statement of when to use this tool versus the many workout-related siblings, nor any prerequisites or exclusions. The only content is pagination defaults, which is invocation detail, not usage guidance.

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