List vendors

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

Annotations already declare read-only, idempotent, non-destructive, open-world, so the safety bar is low; the description still adds substantial undisclosed behavior. It states the tax identifier is never returned by value, that returned data flows to the AI client and can reach that client's model provider, and that free-text fields are untrusted model input rather than instructions — a prompt-injection disclosure no annotation conveys.

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 purpose and the key filtering rule, then the safety/data-handling notes. The final sentence is long and stacks three ideas (free text, private identifiers, untrusted input) but each carries real signal, so little 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?

An output schema exists, so return shape need not be described; what remains — the required entity key, default active filtering, projection/privacy limits, and data-flow and injection caveats — is all covered. For a five-parameter read-only list tool, nothing an agent needs in order to call it safely is missing.

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 all five parameters are already documented in the schema. The description restates the 'active=null includes inactive' semantics and adds the 'never the value' nuance for the tax identifier, but adds no syntax or format detail for limit, updated_since, or vendor_1099 beyond what the schema already says.

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?

The first sentence names a specific verb and resource ('List a company's vendors') and enumerates the projected fields returned (1099 flag, balance, tax-identifier presence). That is enough for an agent to tell it apart from list_customers, list_accounts, and summarize_vendor_payments without opening any 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?

The description gives real usage context: an explicit 'entity' is required and 'active=null' is the way to widen the result set beyond the default. However, it never names an alternative or says when NOT to use this tool — notably it doesn't route to summarize_vendor_payments for aggregates or list_changes for deltas, which an agent could easily confuse with this call.

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