ephemeris_planet_position

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

Annotations already indicate readOnlyHint=true and destructiveHint=false. The description adds transparency by detailing the computed values (longitude, latitude, distance, speed, retrograde status) and the credit cost (1 credit per call), going beyond annotations.

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 with two short paragraphs. The first explains functionality and planet IDs, the second notes cost and gives an example. No unnecessary words; structure is efficient.

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?

Despite lacking an output schema, the description fully explains what the tool returns (ecliptic longitude, latitude, distance, speed, retrograde status). This is complete for a positional lookup tool, and 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?

Schema coverage is 100%, so the schema already defines all parameters. The description adds value by listing planet IDs in a compact format and providing a concrete example, which aids understanding but is not essential beyond the schema.

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 it retrieves precise ecliptic longitude, latitude, distance, speed, and retrograde status for a single planet/body at a given date and time. It lists planet IDs and provides an example, making the purpose unmistakable and distinct from sibling tools.

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 gives context for when to use this tool (single body position at a specific time) and mentions credit cost. While it doesn't explicitly state alternatives or when not to use, the clear purpose and sibling list make appropriate usage inferable.

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