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

With no annotations provided, the description carries the full burden of behavioral disclosure. It indicates a read-only operation ('Fetch') and describes the return format ('Returns a list of planets with their id (index), name, and sector'). However, it does not disclose potential edge cases like pagination, sorting, or error conditions, which are relevant for a list endpoint.

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 a single, front-loaded sentence that directly states the action and return value. It is succinct with no redundant information, and every word adds value.

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?

Given the simplicity of the tool (no params, no output schema), the description adequately covers the essential behavior and return fields. However, it could explicitly state that the list includes all planets without pagination or filtering, though this is mostly implied by 'all planets'.

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?

The tool has zero parameters, so the description does not need to explain parameter meanings. The baseline for 0 params is 4, and the description adds clarity by noting the return fields, providing context beyond the empty 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 the tool's purpose: 'Fetch a list of all planets in the current galactic war.' It specifies the exact resource (planets) and action (fetch list), making it distinct from sibling tools like get_planet_details, which implies fetching a single planet.

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 when a complete list of planets is needed, but it does not explicitly contrast with alternatives or state when not to use it. For example, it doesn't mention that get_planet_details should be used for specific planet details. The implied guidance is enough but lacks explicit direction.

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