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

With no annotations, the description carries the full disclosure burden and does well: it states what compact destroys (EXIF and geolocation), what scan physically does (locate the sheet, correct perspective, whiten background), and how page sizing behaves. It does not cover limits (photo count, file size) or auth, but the transformation behavior is unusually well disclosed.

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 in the first clause, then a tight per-parameter breakdown — each line earns its place. Slightly dense, but there is no filler or repetition.

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?

An output schema exists, so return values need no explanation, and all six parameters plus the key behavioral transformations are documented. The only omissions are operational limits (max photos, size caps) and failure behavior, which the description never addresses.

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 0%, yet the description documents all six parameters: file_urls (public URLs, accepted formats, order = page order), page (a4|photo with meaning of each), compact (default true plus effect), grayscale, scan, and scan_color (bw|color with the scan-only constraint). It fully compensates for the empty schema and supplies the enum values the schema lacks.

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 ('Собирает фото с телефона в PDF: каждое фото — страница') and immediately clarifies the multi-page batching semantics, which cleanly separates it from sibling single-image converters like jpg_to_pdf and heic_to_jpg. Multiple input formats are named, so an agent knows the scope without opening the 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?

Usage is implied by the functionality (combine photos into one PDF) and the description does constrain scan_color to 'только при scan', but there is no explicit when-to-use vs alternatives guidance — nothing tells the agent when to pick this over heic_to_jpg + jpg_to_pdf or how to handle single vs many photos. Minimum viable routing, one gap.

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