freeagent_mark_invoice_as_draft

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

Annotations declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the description's job is to add state-transition context that the annotations cannot express. It adds none: it doesn't say what a draft status means for the invoice (editability), whether already-draft invoices are rejected or no-op, or whether the transition is reversible. A single clause would have raised this score considerably.

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?

It is a single front-loaded sentence with no filler or redundancy. Brevity is not the problem here; the limitation is that nothing else is said, not that words are 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?

For a one-parameter state-transition tool with annotations and no output schema, the definition is minimally sufficient to invoke it. It omits what the agent most needs to know for correct use: which invoice states allow marking as draft and what happens on an invalid state. Adequate but with clear gaps.

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?

There is only one parameter, and the schema already documents it at 100% coverage with a pattern constraint, so the description need not add detail. Baseline 3 applies since the description contributes no meaning beyond the schema, but nothing is left ambiguous.

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 gives a specific verb+resource pair ('Mark an invoice as draft') scoped to FreeAgent, so the operation is unambiguous. It does not, however, distinguish itself from siblings such as freeagent_mark_invoice_as_sent, freeagent_mark_invoice_as_cancelled, or freeagent_update_invoice, which an agent must choose between.

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?

There is no guidance on when to use this tool versus update_invoice or the other mark_* state-transition tools, and no prerequisites such as whether the invoice must be a sent/paid invoice first. The agent must infer the workflow from the tool name alone.

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