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

With no annotations, the description carries the full burden of behavioral disclosure. It implies a read but never states it, doesn't mention whether invites include pending/accepted state, whether results are paginated, or what the response shape looks like beyond 'unread counts'. The only real disclosure, token secrecy via 'join', lives in the schema rather than the description.

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?

A single short sentence with no wasted words, and the most useful detail (unread counts) is placed last where it still reads clearly. It is efficient but borders on under-specification rather than tightness.

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?

The tool is simple (one optional param, no output schema), so the description didn't need to be long — but there is no output schema, meaning the description must explain what comes back, and 'unread counts' is the only hint. Combined with no verb and no sibling differentiation, an agent lacks enough to call it confidently over 'room' or 'inbox'.

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%, and the token parameter is documented thoroughly in the schema including its source ('from join') and secret-handling warning. The description adds nothing about the parameter, so the baseline of 3 for fully-covered single-parameter schemas 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 noun phrase names the resource ('private rooms and invites') and one return attribute (unread counts), but supplies no verb — an agent must infer whether this lists, fetches, or manages rooms. It also does not distinguish itself from the singular sibling 'room' or from 'inbox' and 'dm', which likely overlap.

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?

There is no when-to-use guidance at all: no statement of when to call this versus 'room', 'inbox', or 'dm', and no preconditions such as needing to have joined first. The agent is left to guess placement from the name alone.

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