vizier_query

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

No annotations are provided, so the description must carry the full behavioral burden. It says 'Query' and 'Cone search,' implying a read-only search, but does not disclose result limits, output behavior, authentication needs, or other operational traits. Only the search method is conveyed.

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 two short sentences with no waste, front-loading the service name and then the specific search method. Every sentence contributes to understanding the tool's operation.

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 five-parameter query tool with full schema descriptions but no output schema and no annotations, the description covers the core operation adequately. However, it does not state what the tool returns or add any behavioral context, leaving some gaps for an agent invoking an external catalog service.

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 100%, so the schema already documents all five parameters including target, radius, catalog, max_results, and lang. The description mentions coordinates+radius and a specific catalog, which maps to some parameters but adds no syntax or format details beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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 verb and resource: 'Query VizieR catalog service' and 'Cone search by coordinates+radius on a specific catalog.' It distinguishes the operation from generic catalog queries by naming VizieR and cone search, but does not explicitly differentiate from siblings such as simbad_query, ned_query, or gaia_cone_search.

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 implies usage by specifying 'Cone search by coordinates+radius on a specific catalog,' which tells an agent the required inputs and scenario. However, it provides no explicit when-to-use or when-not-to-use guidance relative to alternatives, leaving the agent to infer selection.

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