Fields: list

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuine value beyond that by disclosing the exact return payload, which matters because there is no output schema. It stops short of noting permissions or pagination behavior, but the return-shape disclosure is substantive context.

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?

Three dense sentences, zero filler, and structurally front-loaded: what it does, how to invoke it, what comes back, then where to go instead. The return-field enumeration earns its space because no output schema exists.

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 one-parameter, no-output-schema read tool, the description supplies the purpose, the required input, the full return shape, and sibling routing. An agent has everything needed to call it correctly and to interpret the response without additional context.

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% and the single parameter is already documented as 'Entity name'. The description's 'Takes the entity name' merely restates the schema without adding format, naming-convention, or resolution behavior for the entity identifier, so the baseline 3 is correct.

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 ('List fields on an entity') and enumerates exactly what is returned (id, name, label, database type, display type, required/unique/indexed/locked flags). It explicitly distinguishes itself from the two nearest siblings, fields_get and entities_get, so an agent can select it without opening any schema.

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?

Gives explicit routing rules: use `fields_get` when one field's complete definition is needed (relationship target, select options), and `entities_get` for the entity's own settings. This is a clear when-to-use-this vs when-to-use-alternatives statement, not an inference.

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