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

Annotations only declare readOnlyHint=true, so the description carries real weight and delivers: it discloses the derating behavior (Q∝V²), the overcorrection alert triggered by carga_min_pct, the short-circuit/inrush design current (1,5·In per IEEE C37.012), and that the call is free. It stops short of describing the full output shape (e.g. required kvar), so a 4 rather than 5.

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 the core purpose and meta, then one clause per optional parameter. Dense but every sentence carries engineering meaning; the capitalization and backticked parameter names aid scanning, though the paragraph is long for a single block.

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?

With 8 parameters, 0% schema coverage and no output schema, the description supplies the missing semantics for the non-obvious inputs and indicates what extra results (nominal current, standard, overcorrection alert) appear under certain inputs. Remaining gap is the exact shape of the primary result (capacitor bank kvar).

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 0%, so the description must compensate and largely does: it explains tensao_kV, Un_cap_kV, carga_min_pct, scc_MVA and the fp_meta default in domain terms. potencia_kW, fp_atual and api_key are left implicit, but their meaning is evident from the 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 ('Dimensiona o banco de capacitores para corrigir o fator de potência'), the target regulation (REN ANEEL nº 1.000) and the default meta (0,92). Distinct from siblings like dessintonia_capacitor, which sizes a detuning reactor rather than the correction bank itself.

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 clear conditional guidance for optional parameters ('Com tensao_kV também dá a corrente nominal', 'informe para não superestimar'), effectively telling the agent when each input matters. It doesn't explicitly compare against sibling tools or state when-not to use it, keeping it short of a 5.

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