List who is editing

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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds the behavioral detail that it returns rows with cursor, selection, and edits, which conveys live collaboration state. It doesn't disclose whether the list is sorted, whether it includes all agents or only some, or whether it requires an active project context, but the annotation covers the safety profile.

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 a single compact sentence that front-loads the core purpose ('People and agents on this project now') and then specifies the row structure. Every word earns its place, and it's appropriately sized for a zero-parameter tool.

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?

Given the tool has zero parameters, an output schema exists, and annotations declare read-only safety, the description is nearly complete. It could add a note about whether the list is live/refreshing or a snapshot, but for a simple listing tool the current description is sufficient for an agent to call it correctly.

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?

The tool has zero parameters, so the schema is trivially complete. The description adds meaning by explaining what the returned rows contain (id, name, cursor, selection, edits), which is more about output than parameters. With no parameters to document, the description doesn't need to compensate for any schema gaps, so a baseline of 4 is 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?

The description 'People and agents on this project now: rows [id,name,cursor,selection,edits]' clearly identifies the tool as listing current editors and their activity, with a specific verb ('list') implied by the title and the row structure. It distinguishes itself from sibling tools like 'annotations' or 'checkpoints' by focusing on live editing presence rather than project content. However, it doesn't explicitly name a sibling alternative, so it's clear but not fully differentiated.

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?

The description implies this is a real-time status tool for seeing who is currently editing, which is a clear context for use. It doesn't explicitly state when to use it versus alternatives like 'checkpoints' or 'undo', but the live-activity framing makes the usage context reasonably clear. No exclusions or alternative routing are provided.

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