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

With no annotations, the description carries the full behavioral burden. It does disclose the key trait that the result becomes non-editable and that form fields/annotations are baked in, which is useful consequence-level context. It does not cover permissions, input-file side effects, or processing behavior for a one-way transform.

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 short lines, front-loaded with the action, then the behavioral consequence, then the parameter. No filler. Slightly terse rather than verbose; nothing is wasted.

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 single-parameter tool with an output schema (so return values need no explanation), the description covers purpose, effect, and the one parameter's requirement. Adequate; only minor gaps around processing/permission behavior remain and those are lower stakes here.

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 0% (file_url is a bare string), so the description must compensate, and it does: 'публичный URL PDF-файла' adds the crucial requirement that the URL must be publicly reachable and the file a PDF. That is meaningful semantics beyond the schema's untyped string.

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 and clarifies what flatten actually does mechanically: 'впечатывает поля форм и аннотации в страницы' (bakes form fields and annotations into the pages). This is unambiguous and no sibling overlaps (none of the other tools flatten). It stops short of explicitly distinguishing itself from siblings, so 4 rather than 5.

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?

'идеально для госорганов и печати' (ideal for government agencies and printing) gives an implied use context for when the non-editable output matters, but there is no explicit when-to-use vs. alternative guidance (e.g., vs. protect_pdf or sign_pdf, which also touch form/annotation handling). Usage is inferred, not directed.

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