rhino_bridge_select_instance

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

The description discloses a meaningful side effect beyond the annotations: 'The active bridge client is closed; the next tool call goes through lazy promotion against the new endpoint.' This tells the agent the operation mutates the bridge state, consistent with readOnlyHint=false. It adds behavioral context that annotations alone do not provide.

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 compact and front-loaded: the purpose appears in the first sentence, the selection constraint in the second, and the behavioral consequence in the third. Every sentence contributes essential information without 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?

For a small state-switching tool, the description covers purpose, selector constraint, and session-targeting behavior. The schema documents individual selectors, and an output schema exists, so return-value details are not required. It could have mentioned the related instance-listing tool for discovery, but that is a minor omission.

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?

Although the schema includes descriptions for each selector, the description adds the critical mutual-exclusion constraint: 'Exactly one selector among pid, port, doc_path_contains, and index should be set.' This is important operational semantics not present in the schema. The description does not restate each parameter's meaning, which is appropriate because the schema already covers those details.

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 opens with a specific verb and resource: 'Switch the next bridge call to target a specific Rhino session.' This clearly identifies what the tool does and its scope. It does not explicitly differentiate itself from the closely related sibling rhino_bridge_list_instances, so it stops short of 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?

The description gives clear operational guidance: exactly one selector among pid, port, doc_path_contains, and index should be set. It also explains the timing—the next bridge call—which situates the tool in a workflow. It does not explicitly name alternatives or exclusions, but for a session-selection tool the usage context is clear.

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