num_cards_due_today

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

No annotations are provided, so the description must carry the full burden. It only states the basic purpose but does not disclose whether the operation is read-only, has side effects, or any performance considerations. The return format is not described, although an output schema exists.

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, concise sentence that front-loads the purpose and includes the key optional filter. No unnecessary words.

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?

Given the tool's simplicity (1 parameter, count output), the description covers the basic purpose and filter option. However, it lacks behavioral context (e.g., if it returns 0 for none) and does not leverage the output schema to explain return values. The presence of an output schema mitigates but does not fully compensate.

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?

The only parameter 'deck' has 0% schema description coverage. The description adds that it is an optional filter, but does not specify whether it expects a deck name or ID, or any format details. More information would be beneficial.

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 purpose: 'Get the number of cards due exactly today' with an optional deck filter. It uses a specific verb 'get' and resource 'number of cards due today', and distinguishes from sibling tools like 'fetch_due_cards_for_review' that return full cards.

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 with the optional deck filter, but does not explicitly state when to use this tool versus alternatives like 'fetch_due_cards_for_review' or 'inspect_cards'. No when-not-to-use guidance is provided.

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