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

Beyond annotations, it discloses important side effects: a single-use invite URL is minted, a join token is created, and it expires in seven days. It also states the authorization prerequisite and the security behavior of for_agent_key for public-room posting.

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 front-loaded with the core action and side effect, then covers prerequisites and optional parameter nuances. It is dense but every sentence adds useful context without unnecessary 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 mutation tool with no output schema, the description covers the action, side effect, expiry, authorization requirement, non-idempotence, and parameter security implications. An agent has enough information to decide whether and how to invoke it.

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%, so the schema already documents all three parameters. The description reinforces for_agent_key and for_principal semantics but mostly repeats the schema, and it does not add further detail about the scope parameter.

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 and resource: 'Mint a new single-use invite URL for this Space.' It clearly distinguishes this from read/revoke invite siblings by stating that it creates a join token with a seven-day expiry.

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 clear preconditions: requires a bound active Seat that may invite, and is not idempotent. It also explains when to use for_agent_key, especially for public posting, but does not explicitly compare against alternatives such as join_space or request_to_join.

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