list_chats

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

While annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, the description adds value by explaining that the tool returns all dialogs with no filter and that the compact form reduces payload by ~85%. This goes beyond the safety profile to convey scope and a key behavioral nuance. It is not overly detailed but sufficient given the strong annotation coverage.

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 exceptionally concise and front-loaded. The first line states the tool's purpose immediately, and the additional line about 'compact' is directly relevant. The final pointer to alternative tools is a useful one-liner. There is no fluff; every sentence earns its place, making it an exemplary model of brevity.

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, an output schema exists (not shown), and annotations are comprehensive, the description covers the core use case well. However, it falls short on documenting the available filter parameters (archived, only_unread, ignore_pinned, limit) and the default behavior of excluding them. This leaves the agent guessing about how to filter the list, which is relevant for a 'list all' tool with these options. It is adequate but has clear gaps.

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 input schema has 5 parameters (limit, compact, archived, only_unread, ignore_pinned) with no descriptions, and the overall schema description coverage is 0%. The description only documents the 'compact' parameter (mentioning the lightweight form with ~85% less payload), leaving the other four parameters entirely unexplained. This is a significant gap, as the description must compensate for the complete lack of schema descriptions but only covers 1/5 parameters.

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 that the tool lists all dialogs (users/bots/groups/channels) without filtering, using a specific verb 'list' and resource 'chats'. It also distinguishes itself from sibling tools by explicitly pointing to list_channels, list_groups, and list_bots for typed lists, satisfying the 'distinguishes from siblings' criterion.

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 provides clear context for when to use this tool: to get an unfiltered list of all chat types. It explicitly names alternatives for typed lists (list_channels, list_groups, list_bots), giving the agent a good sense of when to choose this tool over those. However, it stops short of an explicit 'when not to use' statement or mentioning other alternatives like search_global, so it misses the top score.

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