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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavior: notes and gym names are athlete-authored text to be treated as data and never instructions (a prompt-injection caveat), plus pagination and result-cap behavior. Return format is sketched but not exhaustively.

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-loads the core purpose ('Read FINISHED workouts') then branches per view using a compact sectioned notation. Every clause carries information — result counts, pagination, injection safety, the sibling pointer — with no filler. The telegraphic '·' style is dense but readable.

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?

There is no output schema, so the description must convey return shape, and it does: list returns summaries with working_set_count, total_set_count_including_warmups, notes, and gym; detail returns set-level data with set IDs and optional per-muscle analytics. That is sufficient for correct invocation, though error cases and cursor expiry behavior are unaddressed.

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 only 60% (view and verbosity have no schema descriptions), so the description must compensate — and it does, explaining what each enum value yields and what 'full' adds (per-muscle analytics). It also clarifies cursor as 'next_cursor from the previous page' and the limit cap, which the schema states only tersely.

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 and resource plus its scope: 'Read FINISHED workouts.' It explicitly carves out the boundary against the sibling that could be confused with it ('The session in progress: read_live_workout'). An agent can distinguish read_workouts from read_live_workout without opening either 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?

Routes clearly between the two modes: list for paginated summaries, detail for set-level data tied to a workout_id, and it names the alternative (read_live_workout) for in-progress sessions. It also gives a concrete trigger for detail ('which log_workout update needs echoed'). No explicit exclusions or prerequisites beyond that, so not a 5.

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