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

Annotations already establish readOnly/destructive=false/openWorld=false, so the safety profile is covered. The description adds genuinely new behavior: it is free, its output is partial (only guidelines it recognizes), and it advertises the price and route of the paid upgrade — useful context an annotation cannot express.

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 sentences, front-loaded with the trigger, then cost, then return shape. Dense but essentially waste-free; the price/route sentence is slightly parenthetical but justified for an agent deciding on the upsell.

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?

No output schema exists, so the description carries the return-value burden and does so: recognized sections with meanings, unrecognized sections listed, plus pricing and routing for the paid version. Nothing an agent needs to call and interpret the result 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 100%, so the single parameter is fully documented with its 20 KB limit. The description reinforces that the input is the raw pasted rejection text, but adds no format or normalization guidance beyond the schema.

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 (explain) and resource (an App Store rejection message's cited guidelines), plus exactly what it returns: recognized guideline sections with title and meaning, and the unrecognized ones. No sibling in this set covers App Review rejections, and the free-preview scope is unambiguous.

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?

Opens with an explicit activation condition ("Use when the user pastes a rejection message from Apple App Review" including how to recognize one, e.g. 'Guideline 5.1.1(i)'). It also routes the agent away from over-promising by naming the separate paid call that provides causes, fixes and a reply draft.

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