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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral detail beyond annotations: it notes that lessons are included 'where available' (i.e., some areas may lack coverage), that the plan personalizes via 'weak areas', and that free FAA references are appended. This gives an agent a better sense of what the tool will and won't produce.

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?

The description is a single dense sentence that front-loads the core purpose ('Builds a dated study plan from today to the exam date') and then lists the plan components. It is efficient, but the parenthetical about Part 107 makes the sentence slightly convoluted and could be clearer with better structuring.

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 tool with 3 parameters and no output schema, the description covers the plan's structure well but leaves gaps: it does not mention the hours_per_day parameter or its effect, does not clarify what 'weak areas' means or whether a prior diagnostic is required, and does not describe the return format. Annotations cover safety but not these operational details.

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 67% (exam and exam_date are described; hours_per_day is not). The description adds some context around exam_date ('from today to the exam date') and mentions 'Part 107' which partially aligns with the exam enum, but it does not explain hours_per_day or how it affects the plan. Since the schema already documents most parameters, the description provides only marginal additional parameter semantics.

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 clearly states a specific verb ('Builds') and resource ('dated study plan'), with a detailed breakdown of what the plan includes. However, the parenthetical '(Part 107 in proportion to the official FAA weights)' is confusing because the tool accepts multiple exam types (ppl, ifr, cpl, atp) and the description does not clarify whether this applies only to part107 or to all exams.

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 provides clear context for when to use the tool: when a user needs a day-by-day study plan leading up to an FAA exam date. It does not explicitly mention alternatives or exclusions, but none of the sibling tools (e.g., exam_facts, compare_prep_options) appear to offer the same functionality, so the usage context is sufficiently clear.

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