list-entity-fields

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

With no annotations, the description carries the full burden. It discloses the read-only, metadata-listing nature ('List the field names') and the intended sequencing ('before passing fields to get-* tools'). It does not mention return format or error behavior, but for a simple enum-limited tool this is adequate.

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?

Two sentences with no filler. The core purpose is front-loaded in the first sentence, and the second sentence adds immediate actionable usage guidance. Every word earns its place.

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 tool with one parameter and no output schema, the description covers what it does and when to call it. It could be more complete by stating the return shape explicitly, but the phrase 'List the field names' sufficiently conveys the output, and the sibling references orient the agent well.

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% since the 'entity' parameter includes an enum and its own description. The tool description adds context beyond the schema by explaining that the parameter selects which entity's field names to retrieve for use with get-* tools, enriching the parameter's semantic role.

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 function with a specific verb and resource: 'List the field names available on a SAP entity.' It distinguishes itself from sibling data-retrieval tools by positioning itself as a helper for the get-* tools, so an agent immediately understands this returns metadata, not entity data.

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?

Explicit usage guidance is given: 'Call this before passing `fields` to one of the get-* tools, instead of guessing field names.' This tells the agent when to invoke the tool and frames it as the alternative to guessing, which is clear direction for tool selection.

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