list_chats

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

Annotations already provide readOnlyHint, destructiveHint, idempotentHint. The description adds that it reads local cache, works while disconnected, is read-only with no side effects. This adds value beyond annotations without contradiction.

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 three sentences, front-loaded with the core purpose, and every sentence adds necessary information. No waste.

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 5 parameters with good schema coverage, no output schema, but description mentions returns JSON array of chat objects with details. It explains offline behavior and side-effect-free nature. Slightly incomplete on return format specifics, but adequate.

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 has 100% coverage with descriptions for all 5 parameters. The description adds context about filtering by name substring and sorting by recency or alphabetic name, and mentions return format. This adds marginal value 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?

The description states it lists cached WhatsApp chats (1:1 and group) with optional filtering and sorting. It distinguishes from siblings by mentioning get_chat for a single chat and list_groups for groups only.

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?

It explicitly says to use get_chat for a single chat by JID and list_groups for groups only. It also mentions it reads local cache and works while disconnected, but does not explicitly state when not to use it. This is clear context.

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