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

Annotations already declare readOnlyHint=true, so the description doesn't need to restate safety. It adds the pagination method (keyset on flashcards.id) which is useful behavioral context, but doesn't disclose details like whether results are sorted, or if the cursor is opaque. No contradiction with annotations.

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?

Two sentences, zero waste. The first sentence states the purpose, the second provides the pagination detail. Front-loaded and efficient.

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?

The tool is simple (3 optional params, no output schema) and the description covers the core purpose and pagination. However, it doesn't mention what the response contains (e.g., word objects, metadata) or any ordering guarantees, which could be important for an agent. Given the simplicity, it's adequate but not complete.

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 only 33% (only 'lang' has a description). The description adds context for 'lang' (user's primary learning language default) but doesn't explain 'limit' or 'cursor' beyond schema constraints. Since coverage is low, the description should compensate more, but it does add some value for the lang parameter.

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 the tool returns words the user has verified as known via flashcard practice, with a specific pagination method (keyset on flashcards.id). It distinguishes from siblings like get_active_vocab and get_queue by focusing on known words, though it doesn't explicitly name alternatives.

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 implies usage for retrieving known words but doesn't explicitly state when to use this vs. alternatives like get_active_vocab or check_words. The pagination hint is useful but no exclusions or alternative tool names are provided.

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