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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the description's remaining job is to add context beyond that. It does: it states the change is IRREVERSIBLE and imposes a user-confirmation workflow, which is genuine operational guidance the annotations cannot express.

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 purpose is correctly front-loaded and the whole definition is short, but the literal duplication 'IRREVERSIBLE. IRREVERSIBLE:' is wasted space in an already terse description. Emphasising the risk once would have been equally effective.

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 single-parameter deletion with no output schema, the description covers what an agent needs: what is removed, that it cannot be undone, and that the user must confirm first. Only the absence of alternative routing keeps it from being fully complete.

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% (workoutId is documented as 'Numeric id'), so the schema already carries parameter meaning. The description adds nothing about what ids are valid or whether string ids are accepted, which is the correct baseline-3 outcome when the schema does the heavy lifting.

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?

States a specific verb+resource ('Deletes a workout from the library') that is unambiguous against the large sibling set, including the nearby delete_activity, delete_course and delete_training_plan. It does not explicitly contrast itself with those siblings, but the resource noun alone is enough to disambiguate.

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?

Gives an explicit precondition: confirm with the user before calling. That is actionable guidance rather than an implication. It stops short of naming alternatives (e.g. update_workout or unschedule_workout for non-destructive needs), so it is not a full when/when-not treatment.

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