groupChat_addParticipants

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

With no annotations, the description carries the full burden of behavioral disclosure, but it merely restates the schema. It does not mention side effects, permission requirements, whether participants are added silently or trigger invites, rate limits, or error conditions.

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 very brief and front-loaded, but the two sentences are slightly redundant ('Add the participants' and 'Add a list of participants...'). Still, it is concise and wastes no words, though it could consolidate the message.

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 tool with a nested options object and four parameters, the description is under-specified. It omits return values (no output schema), prerequisite conditions, and the specific behavior when adding participants. The schema covers parameter names but not the tool's overall context, making this insufficient for complex usage.

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%, so the baseline is 3. The description's phrase 'by ID' adds no information beyond the schema's 'participantIds' description. It does not explain the 'options' object structure or that 'chatId' is required conceptually despite not being marked required.

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 the action ('Add') and the resource ('participants' to 'the group'), making it unambiguous. It distinguishes itself from sibling tools like groupChat_removeParticipants and groupChat_promoteParticipants by specifying the add operation.

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?

No guidance is provided on when to use this tool versus alternatives, nor any mention of prerequisites (e.g., admin rights, group membership). The description only states the action without contextualizing it among the sibling group management tools.

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