list_signals

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

With no annotations, the description carries the full disclosure burden and does so well: it discloses that the tool internally uses the deprecated sdv.databroker.v1.ListMetadata RPC, states that query matching is a case-insensitive substring on the signal path, and describes default scope behavior. It stops short of edge-case behavior such as errors on invalid branch paths, but covers the key behavioral facts.

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?

Front-loaded with purpose and deprecation in the first line, followed by usage rules and an Args reference. There is slight redundancy — the prose usage instructions essentially restate what the Args section repeats — but no sentence is wasted overall.

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 two optional parameters, an existing output schema (so return values need not be explained), and no annotations, the description covers purpose, filtering semantics, defaults, deprecation, and alternatives. The only notable omission is behavior on invalid branch paths, which is minor for a list/discovery tool.

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%, and the description fully compensates with an Args section that explains branch as a VSS path with concrete examples ('Vehicle.Cabin') and query as a case-insensitive substring with examples ('Speed', 'Temperature'). This adds real meaning beyond the schema's bare titles and defaults.

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 first sentence states a specific verb and resource — 'List signals and their metadata under a given VSS branch' — with an explicit API tag. The deprecation header and the note preferring get_signal/get_signals for known paths clearly separate it from sibling tools in the same signal domain.

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?

Explicit when-to-use guidance: 'Prefer browsing signals via get_signal / get_signals with known paths when possible' names the alternative and the condition that selects it. It also explains both usage knobs (branch scoping, query filtering) and documents the default full-tree behavior when both are empty.

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