search_sources_near_position

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

With no annotations, the description carries the behavioral disclosure burden. It adds the key behavior of returning sources within a radius and the auto-resolution of coordinates from a source_id. However, it does not disclose authentication requirements (other than in schema), rate limits, or behavior when no parameters are provided, which limits transparency.

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 concise (three sentences) but has minor redundancy: 'Search for sources near a position' is repeated in 'Finds all sources within a specified radius.' Overall it is well-structured and front-loaded with the core purpose.

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 the tool's purpose, usage context, and key input alternatives. An output schema exists, so not explaining return values is acceptable. It could mention edge cases (e.g., if neither ra/dec nor source_id is provided), but the description is reasonably complete for a search 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 coverage is 100%, so baseline is 3. The description adds value by explaining the either/or relationship between ra/dec and source_id, helping the agent understand valid input combinations. This goes beyond the individual parameter descriptions.

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 a specific action ('Search for sources in SkyPortal near a position') and explains it as a cone search. It distinguishes from siblings like generate_cone_search_code by focusing on the actual search operation, not code generation.

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 provides clear use cases: 'checking if a source already exists... or finding nearby sources.' It does not explicitly mention alternatives or when not to use, but the context is sufficient for an agent to understand appropriate use.

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