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

Beyond the annotations' general mutation and safety signals, the description usefully discloses that saving may replace an existing routine and that replacement involves both id and version. It does not explain version-mismatch behavior, the scope or recoverability of replacement, or what a successful save returns.

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?

Two compact sentences front-load the resource, its purpose, and both save modes. The parenthetical definition and final workout comparison add useful information without repetition or filler.

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?

Together with the detailed exercise and set schema, the description provides enough context to select the tool and construct either a create or replace call. Explicit sibling routing and brief details about version conflicts and the save result would make it more complete, especially because there is no output schema.

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?

With only 29% schema description coverage, the description partially compensates by explaining how id and version select replacement and by relating the exercise payload to a workout without a day. The workout analogy is not self-contained, and undocumented top-level fields such as summary and notes receive no additional semantic guidance.

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 gives specific create and replace operations for a routine and defines it as "a reusable workout plan the person starts from the app." "Same shape as a workout, without a day" also distinguishes its payload and purpose from the sibling workout-saving tool.

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?

It clearly directs creation without an existing identity and replacement "given its id and version," while the reusable-plan definition supplies context for choosing a routine rather than a workout. It does not explicitly name alternatives such as trainrec_save_workout or trainrec_plan_workout or state when not to use them.

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