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

Annotations only provide a title (no readOnly/destructive hints), so the description carries the burden of behavioral disclosure. It does add a meaningful side-effect (governance state applied immediately), but omits details like authentication, reversibility, or failure behavior. This is adequate but not rich.

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 extremely concise: two sentences, front-loaded with the action and resource, and every word earns its place. It includes the essential ordering hint without fluff.

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 join operation with one parameter and an output schema, the description covers purpose, ordering, and a side-effect. It does not elaborate on governance specifics or return values, but those are either covered by the output schema or not critical for this tool.

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% for the 'name' parameter, which already explains its purpose (sender identity). The description adds no additional parameter-specific detail, so the baseline score of 3 applies.

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 (Join) and the specific resource (governed CIVITAE COMMAND channel), and further distinguishes itself from siblings by noting it is a prerequisite for chat_read and chat_send. This is a specific and unambiguous purpose.

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 explicitly provides when-to-use guidance: 'Call this before chat_read or chat_send.' This is a strong usage signal. However, it does not mention alternatives or when not to use it, so it falls short of a full 5.

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