contacts_modify_group_members

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

With no annotations, the description must carry the full burden of behavioral disclosure. It only says 'add or remove contacts' without explaining side effects, idempotency, permissions, or how existing members are affected. For a mutation tool, this is a significant gap.

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 a single concise sentence with no wasted words. It is front-loaded with the action and appropriately sized, even though it is sparse in content.

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?

Given the tool's complexity (3 parameters, mutation, no annotations), the description is too sparse. It doesn't explain operation semantics, input expectations, or edge cases, and it fails to compensate for the lack of schema descriptions. An output schema exists, but the description still leaves critical unknowns.

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 0%, so the description must compensate. It only hints that contacts are added/removed and that a group is involved, but it doesn't explain parameter formats, mutual exclusivity, or requiredness. The parameter names are self-explanatory, but the description adds little beyond them.

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 tool's function: 'Add or remove contacts from a contact group.' It uses specific verbs and a specific resource, and it distinguishes from sibling tools like contacts_create_group or contacts_update. The name and description are well-aligned.

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 gives no guidance on when to use this tool instead of alternatives. It lacks prerequisites, exclusions, or references to sibling tools like contacts_batch_create/delete. The usage context is entirely implied, not stated.

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