Establish a project session with explicit identity and optional parent context, then receive a compact status with map recovery to coordinate ongoing work.
Join with explicit session identity and optional parent; return compact status with map recovery.
| Name | Required | Description | Default |
|---|---|---|---|
| request | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already provide idempotentHint=true, readOnlyHint=false, and destructiveHint=false, so the description's job is to add context. It adds only that the tool returns a 'compact status with map recovery,' which is vague and does not clarify side effects, persistence, or authorization requirements. No contradiction with annotations, but the behavioral insight is minimal.
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 with no filler. It front-loads the main action ('Join') and then mentions the return behavior. Some terms are cryptic ('map recovery'), but structurally it is efficient and avoids redundancy.
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?
This tool has a complex nested request object with seven required sub-fields, yet no output schema exists and the description does not explain most of these fields or the meaning of 'map recovery.' The lack of usage context, side-effect details, and parameter semantics leaves the definition incomplete for an agent to invoke it confidently.
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 coverage is 0%, so the description must compensate for the nested request object and its many required fields. The description only hints at two concepts: 'explicit session identity' (likely external_session_id) and 'optional parent' (likely parent_session_id). It does not explain required fields like repository, vendor, runtime, model, or request_id, nor optional fields like effort or take_over_from.
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 ('Join') and a resource ('session'), which gives some direction, but the meaning is vague: 'Join' could mean joining a project, a session, or a workspace. 'return compact status with map recovery' is jargon that is not explained and does not clearly distinguish this from sibling tools like work_claim or project_status.
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 guidance on when to use this tool versus the sibling tools. The description implies a use case ('Join with explicit session identity') but does not mention alternatives, prerequisites, or exclusions. An agent cannot tell whether this is the right tool for session initialization, reconnection, or something else.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.