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

Beyond the destructiveHint/idempotentHint annotations, the description explains the key behavior: the call stages a proposal rather than mutating the plan, supersedes prior pending proposals (explaining the non-idempotent flag), and requires user acceptance in the iPhone app. It also preempts a plausible confusion by noting the coach-note write switch does not govern proposals.

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 compact sentences, front-loaded with the core action and scope, followed by lifecycle and authorization details. No filler or redundancy; the final sentence about the coach-note switch earns its place as a disambiguation.

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For a mutation tool with no output schema, the description covers what is created, what gets superseded, and what triggers the actual plan change, which is the essential behavioral picture. It could still say what the call returns (e.g., a proposal identifier) or reiterate the per-call change limits.

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 67%, so much of the parameter meaning is already documented inline, including the action enum and per-action fields. The description only restates the four actions and adds no format, ordering, or constraint detail beyond the schema (e.g., the 14-item cap or date rules).

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 gives a specific verb ('Create a pending proposal') and resource ('future sessions in the active P.R.O. training plan') and enumerates the four supported operations. It is clearly distinguishable from the read-oriented siblings like get_plan_proposal and get_training_plan.

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 conveys a clear usage context: proposals are pending, older pending proposals are superseded, and the plan only changes upon user acceptance in the iPhone app. It does not explicitly name an alternative tool or state when not to call it, so it stops short of full routing guidance.

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