query_vizier

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

No annotations are provided, so the description carries the full disclosure burden, yet it omits that results are capped (default limit 500, max 5000) despite 'whole catalog' implying a complete dump. It also says nothing about read-only nature, return format, or performance characteristics.

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?

A single front-loaded sentence with no filler, and the example does immediately useful work. It is efficient, though the example consumes most of the space that could have gone to limit or catalog 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?

With no annotations and no output schema, the description must cover behavior and results, but it never mentions result caps, the fixed catalog set, or what a record looks like. An agent calling this cannot tell that 'whole catalog' actually returns at most 500 rows by default.

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 only 33%. The description meaningfully expands the 'constraints' parameter (column-key dict with wildcard examples), but leaves the five-value 'catalog' enum and the 'limit' cap undocumented beyond bare schema types. With this coverage, the description should compensate but only does so for one of three parameters.

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?

States a specific verb and resource ('Query a whole VizieR catalog') and gives a concrete example of filtered querying. It implicitly separates itself from spatial siblings like cone_search by saying 'whole catalog', but never names an alternative, so an agent must infer the boundary.

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 phrase 'optional column constraints' plus the Green SNR example shows how to use filtering, but there is no explicit statement of when to prefer this over list_catalogs, cone_search, or search_nebulae, nor any exclusions. Usage is implied rather than stated.

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