Get a single participant

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

Annotations already indicate read-only and open-world behavior. The description adds value by clarifying the exact return fields (role, rights, join date), which is useful for understanding the tool's output. It does not disclose edge cases like missing participants, but the read-only annotation covers the main safety concern.

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?

A single clear sentence, front-loaded with the action 'Return'. No wasted words, easily scannable, and appropriately sized for the simplicity of 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 read-only tool with good annotations, the description adequately states the purpose and return value. It lacks detailed parameter format guidance, but the tool is relatively straightforward and the existing sibling tools (e.g., list_participants) likely cover more complex cases. Overall, it is mostly complete for a single participant lookup.

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 zero schema description coverage, the description offers minimal semantic help: it clarifies that 'peer' refers to the channel/supergroup and 'user' is the target user. However, it does not specify accepted identifier formats (ID, username, phone) or the optional accountId parameter, leaving significant ambiguity for the agent.

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 uses the specific verb 'Return' and names the exact resource properties (role, rights, join date) for a single participant, which clearly distinguishes it from list_participants and other participant-related tools. The scope 'in a channel/supergroup' further clarifies the target context.

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 specifies the context 'in a channel/supergroup' and the singular nature ('one user'), making it clear when this tool is appropriate. However, it does not explicitly name alternatives or when-not-to-use cases, so it falls short of an explicit guideline.

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