Correct a logged set

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

Annotations already signal non-read-only, idempotent, non-destructive behavior. The description adds useful behavioral context beyond annotations: the exact patch key whitelist, the 1-based occurrence semantics for repeated exercises, and the return behavior ('updated set, or null if none'). No contradiction with annotations.

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?

Three dense sentences with no filler. The purpose is front-loaded, allowed keys are compactly listed, and the non-obvious occurrence parameter is explained. Every sentence earns its place.

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?

The description covers the locating key, the mutation scope, allowed patch keys, duplicate-exercise handling, and return behavior. An output schema is present, so the absence of detailed return-field documentation is not a gap. An agent has enough to invoke this tool correctly.

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 the patch object via an explicit allowed-key list and defines the 'occurrence' parameter precisely. The remaining parameters (session_id, exercise_id, set_number) are self-descriptive from their names, though the description does not elaborate on value formats.

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 states a specific verb ('Fix'), a clear resource ('a single set'), and an unambiguous locator ('session + exercise + set_number'). It also enumerates the allowed fields, which distinguishes it from session-level siblings like update_session.

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?

The description clearly implies when to use the tool: when correcting a logged set's metrics. It does not explicitly name alternatives or list when-not conditions, but the scoping by session/exercise/set_number and the allowed patch keys give the agent sufficient context for selection.

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