list_decks

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

The readOnlyHint annotation already indicates this is a safe read operation. The description adds that it returns all decks with new/learn/review counts, but since an output schema exists, this return value information is redundant. No additional behavioral traits such as pagination, performance, or prerequisites are disclosed.

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 brief and front-loaded, stating the core function in the first sentence. The 'Returns:' section adds structure but partly duplicates what the output schema likely provides, making it slightly redundant yet still 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?

Given the tool's simplicity (no parameters, read-only, output schema present), the description is sufficient. It covers the essential function and return contents. However, it lacks any mention of edge cases or limitations, such as how it handles many decks or whether it includes all profiles.

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 tool has zero parameters, so there is nothing to explain. The baseline for 0 params is 4, and the description does not need to compensate for any schema ambiguity since the input schema is an empty object.

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 'List all Anki decks with card counts' states a specific verb and resource, clearly distinguishing it from siblings like create_deck, export_deck, and import_deck. The scope ('all decks') and the inclusion of detailed card counts make the purpose 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?

There is no guidance on when to use this tool versus alternatives. The description only states what the tool does, without mentioning any alternative tools or excluding conditions, such as 'use search_notes for specific notes' or 'use progress for study statistics.'

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