client_getCommonGroups

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

With no annotations provided, the description carries the full burden. It discloses the return behavior for an empty result ('Returns empty array if you don't have any common group') and implies a read-only operation via 'Get'. However, it does not mention any permission requirements, error conditions, or side effects, leaving some gaps.

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 redundant, repeating 'Get the contact's common groups' twice in the first two sentences. This wastes a sentence and could be tightened to a single statement. The useful information about 'with you' and the empty-array return is buried in the repetition.

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 two parameters and no output schema, the description covers the core behavior and the empty-array edge case. It does not elaborate on the content of non-empty arrays or error scenarios, but these are likely inferable from the tool's name and context. Overall, it is reasonably complete.

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 already has 100% description coverage for both parameters (contactId and sessionId). The description does not add extra meaning beyond what the schema provides, so the baseline score of 3 is appropriate.

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 a specific verb ('Get') and resource ('contact's common groups') with scope ('with you'), indicating the groups shared between the contact and the current user. While it doesn't explicitly distinguish it from the similar sibling contact_getCommonGroups, the '[Client]' prefix and phrasing provide enough clarity.

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 no explicit guidance on when to use this tool versus alternatives. There is no mention of prerequisites, exclusions, or comparison to similar tools like contact_getCommonGroups. The usage context is only implied by the purpose itself.

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