rhino_bridge_list_instances

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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds meaningful behavioral context: results are derived from announcement files on this host, rows include an 'alive' flag from a cheap TCP probe, and stale cleanup can delete announcement files. This goes beyond the annotations.

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 compact paragraph: two sentences. It front-loads the purpose, states the output shape, and avoids fluff. Every sentence adds value.

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?

The description covers purpose, output fields, and the core behavioral mechanism. It doesn't explicitly explain that the input is a wrapper object with one nested 'args' property, but the schema is clear. Given an output schema exists, return values need no elaboration. The only gap is that the agent might want to know the ordering of rows or how to select/filter with rhino_bridge_select_instance, but that is a sibling concern, not a required piece.

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 0%, so the description carries the burden. It doesn't document probe_timeout or stale_cleanup, but the input schema provides clear descriptions and defaults for both. Given that the schema fills the gap, the description isn't required to repeat it; the tool's behavior is sufficiently explained elsewhere. Score 4 rather than 5 because the description could briefly mention that env/discovery details are host-scoped.

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 states a specific verb ('Enumerate'), a specific resource ('live Rhino bridge endpoints discovered via announcement files'), and details the output contract. It clearly distinguishes itself from siblings by its focus on the bridge instance registry.

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 tool is for inspecting running Rhino processes and their bridge endpoints. Given the read-only annotations, an agent can infer it is a diagnostic/selection precursor. It doesn't explicitly name an alternative like rhino_bridge_select_instance, but the context and role are clear enough.

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