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

Annotations already declare readOnly/idempotent/non-destructive, so the description doesn't need to restate safety. It adds real behavioral context beyond the annotations: the default window, the 120-day cap on ranges, the state enumeration, and the 'unscheduled' bucket for cards awaiting a day.

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, front-loaded with the core action and return payload, then the default, then the override rule and edge case. No 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?

Although an output schema exists, the description still summarizes the return shape (cards per day, unscheduled group) and covers both parameters and their constraints. Nothing an agent needs to call it correctly is missing.

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 0%, so the description must carry the burden. It documents the format (YYYY-MM-DD), the 120-day-apart constraint, and the default-window semantics for both from/to, fully compensating for the missing schema descriptions.

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 ('Read') and resource ('the Content Planner') and then enumerates exactly what each returned card contains (title, keyword, article type, state, search volume/difficulty). This distinguishes it cleanly from siblings like move_planner_card and list_articles.

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?

Explains the default behavior ('defaults to the window the planner page shows') and the condition for overriding it ('pass from and to for another'). Clear context is given, but no alternative tools are named for related needs (e.g., moving cards).

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