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

Annotations already mark it read-only and non-destructive, and the description adds substantial behavior: returned writable/read-only fields, revision as an optimistic-concurrency token, summary units, target resolved values ignored on write, and note steps not sent to watches. That is meaningful detail beyond annotations and does not contradict them.

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?

It front-loads the purpose and every sentence carries operational detail, but the description is dense and packs multiple field/update semantics into semicolon-heavy prose. Still, little is redundant given the absence of an output schema.

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 no output schema, the description supplies the missing return-value guidance: writable fields, read-only fields to omit from patches, revision token, summary text, and note-step handling. That is complete enough for an agent to read and feed the event into an update call.

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%, so all five inputs are documented in the schema, including id, group/athlete, recurrence_action, and with_description_html. The description adds semantics for returned fields like summary/revision rather than additional input-parameter meaning, so baseline 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 first sentence states a specific verb and resource ('Read a planned training workout') and the required id in the schema makes the single-workout scope clear. It also contrasts its return shape with update_planned_training, though it does not explicitly name list_planned_trainings as the alternative for discovery.

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 explains the round-trip pattern with update_planned_training and warns to request description_html before changing an existing description, which gives useful context. However, it never states when to choose this over list_planned_trainings or other read siblings, nor when not to use it.

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