Get Watchlist source

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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds little behavioral context beyond the id provenance, and it does not contradict 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?

One clean sentence with no filler or repeated schema content. The key constraint, that the id comes from list_sources, is front-loaded and immediately actionable.

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?

With a single required parameter, full schema coverage, comprehensive annotations, and an output schema present, nothing essential for calling this tool correctly is missing. The description is fully adequate for the tool's low complexity.

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?

The input schema fully documents sourceId at 100% coverage, including examples like wallet:12, exchange:binance, and manual:3. The description merely restates the provenance relationship already present in the schema, 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 says 'Look up one Watchlist source by the id returned from list_sources.' This uses a specific verb, names the resource, and clearly indicates singular lookup behavior, distinguishing it from list_sources without needing to inspect 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?

It explicitly states that the id comes from list_sources, establishing a clear call sequence for the agent. It does not explicitly enumerate exclusions or alternatives, but the 'one ... by id' phrasing sufficiently implies the contrast with listing.

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