Strength log

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds substantial context beyond them: local decryption, owner's-sessions-only scope (no partner fan-out), duplicate_sessions already excluded from counts, and detailed `coverage`/`more_available` semantics with a warning not to misreport a limit-shaped window as full history. This is rich behavioral disclosure.

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 and scopes return fields before the operational caveats. It is long and mostly earns its length given the coverage-safety warnings, though the `coverage`/`more_available` instruction block is dense enough to border on over-explanation.

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?

Despite an output schema existing, the description usefully explains the meaning of key return fields (exercise sets, total_volume_kg, duplicate_sessions, coverage block), which the schema alone would not convey. For a 3-param read tool it is complete enough to call correctly and interpret results safely.

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 0%, so the description must compensate. It explains `limit_days` ('cap how many sessions return') and references `limit` indirectly ('re-read with a larger `limit`'), but never explains the `fresh` parameter at all, leaving one of three params undocumented in both schema and description.

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 ('Decrypt recent strength-training sessions locally') with ordering (newest first) and explicitly distinguishes itself from the sibling `get_workouts` by noting it carries exercise-level detail HealthKit's workout type cannot. An agent can pick this over `get_workouts` 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?

Gives clear usage context: join `date` against sleep/HRV/weight for training-load analysis, and pass `limit_days` to cap results. It implicitly contrasts with `get_workouts` via the HealthKit remark, but never explicitly states when NOT to use it or names an alternative to prefer for non-strength data.

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