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

With no annotations, the description carries the behavioral burden. It adds useful state semantics: incoming contacts need acceptance and outgoing contacts are waiting. However, it does not disclose read-only behavior, authentication needs, pagination, or the response shape.

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 and front-loaded, with no filler. The 'Contacts: ...' structure immediately communicates the domain and categories, though it is arguably too 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?

For a tool with no annotations and no output schema, this fragment is too thin. It does not state what the tool returns, whether the optional token is required for authentication, or how the three categories appear in the response. An agent can infer the purpose but not the full calling contract.

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%, and the description does not mention the token parameter at all. Since the description must compensate for the missing schema documentation, and it adds no parameter meaning, this 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 identifies the resource (contacts) and enumerates the three status categories returned: accepted, incoming, and outgoing. This makes the listing purpose clear, though it does not explicitly contrast with sibling contact-management tools like request_connect or accept_connect.

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 given about when to use list_contacts versus alternatives such as request_connect, accept_connect, or list_rooms. The status labels imply it is for viewing contact requests, but there is no explicit when-to-use or exclusion criteria.

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