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

With no annotations, the description carries the burden. It discloses that the computation is pure positional astronomy over validated rise/set/transit times, is longitude-independent, and that date defaults to now. This provides meaningful behavioral context beyond the schema, though it does not discuss return format details.

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 four sentences, each dense with useful information. It avoids redundancy and is well-organized, starting with the core definition and then adding scope and defaults. No fluff or repetition.

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 complex astronomical tool with no output schema, the description provides a solid conceptual foundation, covering the underlying relationship, the latitude-only requirement, and the default date. It does not explicitly describe return values, but the output parameter schema partially covers that gap, making the description contextually complete for typical usage.

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 conceptual meaning by explaining the co-angular relationship, the 24-hour window, and the tolerance concept, which deepens understanding of how 'date' and 'tolerance_min' function beyond their schema 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 precisely defines the tool as computing co-angular bodies (paranatellonta) over a 24-hour window, specifying the four angles and tolerance. It clearly distinguishes from siblings via the longitude-independent, latitude-only geometry, making the purpose unambiguous.

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 conveys that the tool is for longitude-independent parans and notes date defaults to now, but it does not explicitly state when to use this tool over alternatives or when not to use it. The usage context is implied but lacks direct exclusions or sibling references.

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