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

Adds meaningful context beyond the annotations: it explicitly frames the call as a write to the user's books and notes the created vendor can be archived or deleted later, which communicates reversibility. It also names the underlying endpoint (POST /vendors) and the single required field. It stops short of saying what happens on duplicate names or what permissions are needed.

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 sentences, front-loaded with the purpose, then behavior, then the required-field constraint and endpoint. Nothing is redundant or padded.

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 should say what comes back (e.g., the new vendor ID) so the agent knows how to reference the created record. It also omits duplicate-name behavior, which matters for a non-idempotent create. Adequate for the happy path, incomplete for the full picture.

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 only 27% across 11 parameters, so the description should compensate more. It correctly highlights that only display_name is required, which is genuinely useful for an 11-param schema, but the remaining ten fields (email, phone, tax_no, address, billing_address, etc.) get no guidance in either place.

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 ('Create a new vendor (supplier) contact in Jurnal') and disambiguates the synonym 'vendor/supplier'. It doesn't explicitly contrast with jurnal_create_customer, but the resource noun makes the split obvious.

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?

No guidance on when to use this instead of jurnal_list_vendors (to check for duplicates) or how it relates to jurnal_create_customer. The only usage-adjacent hint is 'This writes to the user's books', which is behavioral rather than routing.

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