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

Annotations already establish readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds two pieces of non-structured context: the operation costs no credits and defaults to the user's latest plan when no id is given. It does not discuss rate limits or polling politeness, so a 4 rather than a 5.

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 short sentences, front-loaded with the return value, then usage triggers, then the cost note. Every sentence carries information an agent can act on and none is filler.

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?

An output schema exists, so return-shape detail is unnecessary, and the description covers default behavior, when to invoke, and cost. For a single-optional-parameter read tool this is nearly complete; only polling/freshness expectations are left implicit.

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 100% and the single parameter's schema description ('the latest plan when empty') already covers the fallback behavior. The description's 'Without a plan id, the user's latest plan' restates that rather than extending it, so the 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 description states a specific resource (a plan created by plan_content) and what it returns (per-day clip/video status plus a playable link), which is far more than a restatement of the name. It also ties the tool to its sibling plan_content, so an agent can distinguish it from run_content_plan and plan_content 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?

It gives concrete triggers: 'when the user asks how the month is going or wants the posting list,' and notes the plan card polls it itself, which tells the agent it is safe/redundant to call for UI refresh. There is no explicit when-not or direct contrast with alternatives such as get_story or list_videos, so it stops short of a 5.

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