tg_common_chats

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, so safety is covered. The description adds that results are limited to groups/channels shared with the target person, but it does not disclose ordering, pagination, or other runtime behaviors beyond that scoping.

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 extremely concise: two short clauses with no filler. The core result is front-loaded, and the use-case note earns its place by helping the agent decide when to call the tool.

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?

For a simple two-parameter lookup, the description conveys scope and purpose well. However, it lacks explicit parameter mapping, especially 'limit,' and since there is no output schema, the absence of any return-value description leaves some ambiguity about what the agent will receive.

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?

With schema_description_coverage at 0%, the description carries the full burden for parameter meaning. It indirectly defines 'user' as 'this person,' but the 'limit' parameter is not mentioned at all, leaving one of two parameters unexplained.

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 identifies the resource as 'groups and channels' and specifies the relationship 'you and this person are both in,' which makes the tool's purpose unambiguous. It also distinguishes itself from sibling tools by focusing on shared/overlapping chats rather than general chat info or contacts.

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 use cases: 'where do we overlap' and 'placing an unknown contact.' It does not explicitly name alternative tools or state when not to use it, but the context is specific enough to guide an agent toward appropriate invocation.

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