Resolve a username or id

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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorld, so the safety profile is covered. The description adds only the notion that the output is an actionable chat entity; it says nothing about failure modes for unresolvable handles or about the lookup cost/latency of an open-world operation.

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?

Two short sentences; the capability is front-loaded and the usage condition follows immediately. No filler or redundant restatement.

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 one-parameter, idempotent lookup with no output schema and full annotation coverage, the description supplies enough to invoke it correctly. It could go further by indicating what the resolved chat value looks like or how it is consumed by send, since no output schema defines the return shape.

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 description coverage is 100% and the single 'peer' parameter already documents the accepted forms, including 'me'. The description merely repeats those input forms, adding no format or normalization detail beyond the schema, so the baseline 3 applies.

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?

States a specific verb (turn/resolve) and resource (@username, phone, numeric id → a chat), which is a genuine capability statement rather than a restatement of the title. It does not, however, differentiate from lookalike siblings such as get_chat, whoami, or list_chats, which also return chat/user entities.

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?

"Use it before sending to someone you only know by handle" gives a concrete trigger condition tied to the send sibling. There is no statement of when NOT to use it (e.g. when you already have a known chat id) and no named alternative, so it falls short of the explicit when/when-not/alternatives bar.

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