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

Annotations only declare readOnlyHint=false and destructiveHint=false; the description adds real value beyond that by clarifying the document is non-fiscal and outside the Veri*factu chain, that acceptance happens in the dashboard rather than via this tool, and that the call returns id, number and total. It stays silent on quote numbering/series, which matters given the get_quote_series and set_quote_series siblings.

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 and then the lifecycle and return value. No filler, and each sentence carries distinct information (what it is, what it isn't, what comes next, what comes back).

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 mutation tool with no output schema, it does state the returned fields and the downstream path, which covers the most important unknowns. But with six parameters and near-zero schema documentation, the definition is not complete enough for an agent to populate items, tax_rate or retention_rate confidently.

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 17% (only valid_until is documented), so the description carries the burden of explaining five other parameters, yet it adds no parameter information at all. Nothing explains items structure, tax_rate/retention_rate defaults, notes, or customer_id expectations, leaving the agent to infer semantics from bare property names.

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 quote (presupuesto) for a customer') and immediately qualifies the document type as non-fiscal with no Veri*factu chain, which separates it from create_invoice and the rest of the invoicing siblings. An agent can tell what it produces and what it does not produce without opening the 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?

Gives a clear lifecycle context: create the quote here, mark it accepted in the dashboard, then call convert_quote_to_invoice to produce a DRAFT invoice, naming the sibling explicitly. What it does not state is the inverse routing rule (use create_invoice when the document must be fiscal), which is only implied by the 'non-fiscal' qualifier.

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