squiggle_sources

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

Annotations already declare readOnly, openWorld, and idempotent hints, so the safety profile is known. The description adds valuable behavioral context beyond this: the return structure ({sources:[{id, name, url, icon}]}), the semantic meaning of 'id' as a filter, an example query, and confirmation that no authentication is needed. This is beyond what annotations 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 information-dense. It front-loads the primary purpose, then provides return format, an example, and auth status. There is no wasted prose—every sentence earns its place.

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 simple list tool with no output schema, the description is fully complete: it specifies the purpose, the exact return structure, the relationship to sibling tools, an example, and auth requirements. Given the low complexity and rich annotations, no further context is needed.

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 has 100% description coverage, with clear meaning for both parameters: 'q' (leave as-is) and 'year' (season filter). The description adds an example use of 'q' with the fixed value 'sources', reinforcing the schema, but it does not add further semantic detail beyond the schema. Since schema covers all parameters, a baseline of 3 is appropriate.

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 clearly states the tool's purpose: listing the forecasting models Squiggle tracks and providing sourceid values used by tip tools. It uses a specific verb ('call this first to learn') and directly distinguishes itself from related sibling tools like squiggle_tips and squiggle_ladder by explaining the filtering relationship.

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 instructs when to use the tool: 'call this first to learn the sourceid values the tip tools filter on.' This provides clear context for usage and implies an ordering relative to squiggle_tips and squiggle_ladder. It doesn't explicitly list when not to use it, but the guidance is sufficiently clear for a simple lookup tool.

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