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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world). The description adds real value beyond them: it discloses that no document is created, no signature request is sent, and that each returned result carries a per-item success indicator — implying partial validation outcomes rather than a single pass/fail.

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 sentences, purpose front-loaded, then input mechanics, then a follow-up instruction. The 'the server sends the documented JSON array' clause is slightly redundant/murky but not wasteful enough to hurt scanning.

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 partially compensates by telling the agent results carry success flags. It leaves minor gaps — behavior on unknown field_id, or what a failed validation means — but for a simple two-parameter read-only validator this is nearly complete.

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 both values and account_id are already documented, and the nested field_id/value pair descriptions are complete. The description's 'supply field/value pairs in values' largely restates the schema, adding only the note that it is sent as the JSON request array. Baseline 3 is appropriate.

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 — validating one or more input values against existing field definitions — and immediately narrows scope with 'without creating a document or requesting signatures'. This clearly separates it from the sibling create/send tools like assinafy_create_document_from_template and assinafy_send_pdf_for_signature.

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?

Establishes when to use it: as a pre-flight check before requesting signatures ('Check each result's success before requesting signatures'), and implicitly rules out use for document creation. It doesn't name a specific alternative sibling for the same job, so it stops short of the explicit when/when-not/alternative triad.

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