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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds valuable context beyond those annotations: field type semantics, the readOnly meaning, and the value format rule (string vs array). No contradiction with 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?

Front-loaded with the core purpose, then each subsequent sentence adds necessary operational detail: field structure, usage ordering, alternative tool, and a critical value-format rule. No filler.

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?

With no output schema, the description compensates well by enumerating returned field properties and their meanings, plus the value format caveat. This is complete enough for an agent to invoke the tool and interpret its result.

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 only parameter, documentId, is fully covered by the schema description ('Unique identifier of the document'), so the 100% schema coverage gives a baseline of 3. The tool description adds no extra parameter detail, but none is needed.

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 'Retrieve all form field definitions in a document' uses a specific verb and object, and immediately distinguishes itself from sibling get_document_field_values by noting this tool returns field definitions, not filled values.

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?

Explicitly states to call this before set_document_field_values, and points to get_document_field_values for already-filled values. This gives the agent clear selection and sequencing guidance.

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