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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation behavior is covered. The description adds a useful behavioral note about using the group's name instead of its id when assigning contacts, which is beyond annotation scope. No contradictions.

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 concise, with two sentences plus a side-effect line. It front-loads the primary purpose and includes a practical tip. No unnecessary words.

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 existence of an output schema, return values don't need explanation. However, the description lacks parameter explanations and does not mention any constraints or related tools (e.g., check existing groups). For a tool with zero schema coverage, this is insufficient for confident invocation.

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 explain parameters. It does not explain the meaning of 'notes' or 'shared', nor does it clarify that 'name' is a string and required. This leaves agents guessing about parameter semantics, which is a significant gap.

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 verb 'create', the resource 'contact group', and the purpose 'to organize contacts'. It also differentiates from related tools by explaining how the group's name is used when assigning contacts, which helps distinguish it from set-contact-groups or update-contact-group.

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 implies usage for creating a new group and gives specific guidance on how to reference the created group when assigning contacts, which is helpful. However, it does not explicitly contrast with alternatives like update-contact-group or list-contact-groups, so it's somewhat implicit rather than explicit.

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