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

With destructiveHint=true already declared, the description adds that Formstack persists the prefill server-side and names the return field 'prefilledUrl' (valuable given no output schema). However, it frames the operation as benign link generation and never explains why it is flagged destructive, nor mentions permission/password implications, leaving a real gap against the annotation.

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 tight, front-loaded sentences covering what it does, an example, and the return field, followed by a short endpoint reference. No filler, though the raw 'POST /forms/{formId}/prefill' line is marginally redundant for an agent-level caller.

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, and the description usefully names the returned 'prefilledUrl' plus the fact that the prefill is stored. Combined with 100% schema coverage on all three parameters, an agent has enough to invoke it correctly; only the destructive/persistence semantics are under-explained.

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%, so form_id, fields, and incomplete_password are fully documented in the schema itself, including per-field-type value shapes. The description adds no parameter-level meaning beyond the example values, so the baseline 3 applies.

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 ('Generate a link to a live form with some fields already filled in') and clarifies scope versus other create tools by specifying it produces a URL rather than submitting data. It does not name a sibling to contrast against, but the resource is distinctive enough to distinguish it from create_submission or get_form.

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 customer example ('send a customer a form with their name and account number pre-entered') implies the use case but never states when to choose this over alternatives like formstack_create_submission or when-not to use it. The pointer to formstack_list_form_fields for field IDs lives in the schema, not the description, so the description itself gives only implied guidance.

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