Issue a commercial mandate

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

The description goes far beyond the annotations (which only say readOnlyHint=false, etc.). It discloses that a spending_limit becomes two constraints 'both visible in the audit record', that the mandate is checked before signing so refusals never receive a signature, and lists specific refusal codes. It also states the return value ('Returns the mandate identifier and the signed document'). These are significant behavioral details not derivable from annotations.

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?

The description is longer than typical but well-structured: purpose and usage are front-loaded, followed by key behavioral notes, refusal list, and return value. Every sentence adds necessary information (e.g., audit record visibility, pre-signing checks, refusal codes), so it is appropriately sized for the tool's complexity. It is not minimal, but it is efficient and free of fluff.

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?

Given 15 parameters, 8 required, nested objects, and no output schema, the description is remarkably complete. It covers purpose, usage, side effects (audit record), failure modes (specific refusal codes), and return value. It also explains the global role of the mandate ('Every other tool names the mandate an agent acts under'), providing sufficient context for an agent to use it correctly.

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?

With 100% schema description coverage, the baseline is 3. The description adds extra meaning for spending_limit, explaining it becomes both an amount ceiling and a currency constraint with audit trail visibility, and clarifies the scope requirement that a scope must carry transaction_ids or categories. These enrich the parameter understanding beyond the schema's own descriptions.

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 description states exactly what the tool does: 'Issue and sign a commercial mandate' and defines the document's content ('which organisation an agent represents, which acts it may take, under which limits, for which transaction or category, and for how long'). It clearly distinguishes from siblings like verify_mandate by saying 'Call this once per acting agent before anything else' and noting that every other tool names the mandate an agent acts under.

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?

It explicitly instructs when to use the tool: 'Call this once per acting agent before anything else' and explains its role as a prerequisite for other tools. It doesn't explicitly name alternatives or exclusion conditions, but the 'once per acting agent before anything else' directive provides clear usage context. The refusal conditions also imply when a mandate would not be issued, which indirectly guides usage.

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