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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the safety profile is covered and the description's 'record' verb is consistent with it. The description adds the grade-scale semantics but says nothing about side effects such as rescheduling the card, updating due dates, or whether repeated reviews stack — meaningful context for a non-idempotent write.

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?

A single sentence that front-loads the action and then enumerates the grade scale inline. No filler, no redundancy, and the most decision-relevant detail (the grade values) is present immediately.

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 two-parameter mutation with no output schema, the description covers the critical grade scale but leaves real gaps: it never explains what recording a review does to the card's schedule or how it relates to srs_due. Adequate to invoke, but not complete for an SRS mutation.

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 load. It fully documents the grade parameter's four values, which the schema leaves as a bare integer with no enum, adding genuine value. However, card_id is entirely undocumented in both the schema and the description, so compensation is only partial.

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 and resource ('Record a card answer') and immediately defines the grade scale, so an agent knows exactly what the tool does. It does not explicitly distinguish itself from adjacent siblings like skip_card, defer_card, or mark_known, which is the only thing keeping it out of 5 territory.

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?

Usage is implied: you call this after the learner attempts a card and you supply the recall grade. There is no explicit statement of when NOT to use it or which sibling to reach for instead (skip_card, defer_card, mark_known), so the routing guidance is left to inference.

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