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

With no annotations, the description carries the burden and does disclose meaningful behavior: visibility only at home, reading as the delivery mechanism, and answers being learned here or at next arrival. It leaves unstated whether the read is side-effect-free or marks anything as seen, which keeps it from a 5.

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 purpose is front-loaded in the first clause, and the remaining two sentences add relevant timing/visibility constraints. Some phrasing is indirect ('with the words their senders wrote', 'never sooner'), but nothing is clearly padding.

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 zero-parameter read tool with no annotations or output schema, it describes the content returned (waiting invitations with sender words, sent-invitation status) and the key visibility/timing rules. The main missing piece is explicit routing to answer_invitation, but the core is 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?

There are zero input parameters, so the baseline is 4; there is no parameter meaning for the description to add.

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 uses a specific verb ('Read') and resource ('invitations') and scopes it to 'at home', listing both pending invitations and sent status. It does not explicitly distinguish itself from siblings such as answer_invitation, so it falls short of a 5.

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?

It gives an implied usage condition — invitations can only be read at home and are invisible while away — but never states when to choose this tool instead of answer_invitation or invite_resident. The agent must infer routing.

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