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

readOnlyHint=true already declares the safety profile, and the description adds substantial value by describing the return structure (per-field type, value, options, label, context derived from surrounding printed text). It does not itself mention the async/webhook behavior, but that is fully carried by the schema; 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 action and resource, and the surrounding detail about what 'context' means (left, right, above, below, row, column) earns its place. It is a dense run-on sentence, slightly longer than needed, but nearly every clause conveys information.

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?

There is no output schema, so the description appropriately carries return-value semantics by detailing the field attributes. Combined with 100% schema coverage on inputs and annotations covering the read-only nature, an agent has what it needs, though permission/auth expectations are left unstated.

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%, and each of the three parameters (file, async, webhook_url) is documented in the schema. The description adds no parameter-level syntax or format detail, so this is the expected baseline of 3 when the schema does the heavy lifting.

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 (List) and resource (form fields of a PDF) and enumerates exactly what each field entry contains: type, current value, accepted options, label, and context. It distinguishes itself from fill-pdf-form and visualize-pdf-form, so an agent can tell it apart from siblings 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?

Explicitly routes the agent to the correct siblings: filling goes to fill-pdf-form and spatial visualization goes to visualize-pdf-form. This gives clear downstream context, though it frames alternatives around uses of the result rather than stating when-not to call this tool (e.g. vs read-pdf-content).

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