watchlist_get_by_id

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

No annotations are provided, so the description carries the behavioral transparency burden. It discloses a key behavioral trait: "Refuses rather than guessing when a name matches more than one list," and explains that results are verifiable unlike the 'active' designation. It does not explicitly state read-only behavior or describe error cases for missing ids, but the 'Get' verb and membership framing imply a non-mutating lookup.

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?

Two sentences carry the core purpose, usage context, and a critical behavioral caveat. Every clause earns its place, and the main action is front-loaded before the scoping guidance.

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 single-parameter read tool with no output schema, the description is nearly complete: it explains what is returned conceptually (membership), how to identify the watchlist, when to prefer it, and how it handles ambiguity. It doesn't describe the exact return format or response for missing ids, but the simplicity of the operation makes this a minor gap.

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 100%, and the schema already explains the parameter as "Watchlist id (preferred) or exact name, from watchlist_list." The description's phrase "explicit id (or exact name)" reinforces the schema but does not add materially new semantic detail, so the baseline of 3 applies.

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 action and resource: "Get one watchlist's membership by explicit id (or exact name)." It also distinguishes this tool from the 'active' watchlist concept, which separates it from sibling watchlist_get without needing to open any schema.

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 explicitly says when to use this tool: "This is what a universe scan should use - it is verifiable, where 'active' is not." It contrasts with the alternative 'active' watchlist and adds a concrete behavioral rule about refusing on ambiguous name matches, giving an agent clear decision criteria.

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