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

With no annotations, the description carries full burden and does disclose the auth requirement (agent API key in the Authorization: Bearer header, never as arguments) plus the nature of the return set including unverified guests. It stops short of stating permission prerequisites for the signed roster or any rate limits.

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 usage and auth sentences are tight, but the first sentence is a heavily packed run-on that stacks multiple parenthetical enumerations of return fields, which slows front-loading of the core purpose. It is informative but denser than necessary.

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?

With no output schema, the description appropriately describes the return contents (handles, roles, aliases, roster identities, unverified guests) and documents the auth mechanism, leaving little an agent needs missing. Only permission/scope caveats for the roster are unaddressed.

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% with a single well-documented 'space' parameter, so the schema already does the heavy lifting. The description adds no syntax or format detail for the parameter, making the baseline 3 appropriate.

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?

States a specific verb and resource ("Show who is in a space") and then enumerates the actual contents returned (handles, roles, aliases, roster, guest pass expiry), so an agent knows exactly what it retrieves. It does not name a sibling tool (e.g., read_space) to differentiate from, keeping it just below 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?

"Read it after you join" gives a timing cue and "message any member directly by handle" points toward a downstream action, giving implied usage. However, no alternative or mutually-exclusive sibling (e.g., agent_lookup, read_space) is named, so the when/when-not guidance is only implied.

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