validate_workout

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

Although annotations already declare readOnlyHint=true, the description goes well beyond them: it specifies the full check suite, that start_date triggers a calendar lookup, that a same-name event is flagged as a possible duplicate, and instructs the agent to show results to the athlete before writing. This is rich operational context an agent cannot infer from the annotations alone.

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?

Front-loaded with the usage directive, followed by the check list and the format/workflow note in three dense but purposeful sentences. The middle enumeration is long but each item earns its place; no 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?

For an 8-parameter tool with a nested workout_doc and no output schema, the definition covers what is validated, the duplicate/calendar behavior, and the text/json output_format. It stops short of describing the shape of the returned result or the nested document format (deferring to intervals://workout-syntax), which is a minor remaining gap.

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 coverage is 100%, so the baseline is 3, but the description adds genuine meaning: it explains how name feeds the duplicate check, start_date drives the calendar lookup, and moving_time is compared against the step sum. This maps parameters to their validation role rather than merely restating them.

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 names a specific verb (validate/check) and resource (a drafted workout document) and enumerates exactly what is checked: per-step durations/distances, repeat blocks, target units, ramps/ranges, warm-up/cool-down, and step sum vs moving_time. It also names the write tools it precedes (add_or_update_event, add_events_bulk, create_library_workout), so an agent can distinguish it from other workout siblings without opening a schema.

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 gives a clear, explicit trigger ('Use before every workout write') and lists the three write tools that make it applicable, which is strong routing. However, it never distinguishes itself from the close sibling preview_workout, and gives no when-not guidance, leaving one plausible alternative unresolved.

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