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

Adds substantial behavior beyond the annotations: hand-setting converted status or converted_invoice_id is refused, converted quotes are frozen because re-converting could double-bill, and tax fields are creation-fixed. The annotations already declare readOnly=false, idempotent=false, destructive=false, and the description is fully consistent with them, while supplying operational consequences the annotations cannot express.

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 dense but front-loaded: it states what is editable, then the two hard constraints (frozen converted quotes and creation-fixed tax fields), then the next action. Every sentence carries operational information and there is no filler.

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 13-parameter mutation with no output schema and low schema description coverage, the description covers the high-risk semantics an agent must know to avoid double-billing or failed updates. It does not explain response shape or every editable field, but the remaining fields are largely self-explanatory and quote_read exists as a companion, so the definition is largely complete for safe invocation.

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 15% (only id and expected_updated_at are documented in the schema), so the description must compensate. It does add critical semantics for status, converted_invoice_id, tax_scheme, prices_include_tax, and tax_rate_bps, but it leaves notes, currency, client_id, issue_date, valid_until, and quote_number undiscussed. The non-obvious constraints are covered, but not enough to fully compensate for the low schema coverage.

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 opens with a specific verb and resource ('Edits a quote's header fields and bookkeeping status') and immediately scopes what 'header' excludes by contrasting it with convert-flow-owned fields. It also names the relevant sibling (quote_convert), so an agent can distinguish it from quote_item_update, quote_create, and quote_convert 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?

Explicitly states when status moves are allowed ('draft, sent, accepted, declined move freely') and when they are not ('converted quote is frozen: no status move and no header edit'). It also names the correct alternative for invoice creation ('NEXT: quote_convert to create the invoice and record the link atomically'), giving the agent both the exclusion and the successor action.

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