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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond that: it discloses the payment model ('pague por consulta com crédito pré-pago'), the data sensitivity level ('não é dado sigiloso' — not confidential, same as available to citizens), and the LGPD compliance responsibility for the client. It does not contradict annotations — the query/download operation aligns with readOnly. The description enriches the annotation baseline with cost and legal/regulatory context rather than repeating what annotations already state.

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 two sentences of moderate density with the core purpose front-loaded ('Enel CE: Download, consulta em fonte oficial'). Each clause earns its place: purpose, hosting/auth model, payment method, data source and sensitivity, LGPD responsibility. No filler or redundancy. It could be slightly restructured for scannability, but it is compact and efficient — this reads as concise specification, not under-specification.

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?

This is a paid, external-service query tool with 4 parameters (3 required), no output schema, and 0% schema coverage. The description covers the high-level context (purpose, payment, data nature, legal responsibility) but omits several essential operational details: what the return values look like, how to obtain 'instalacao' and the Enel login credentials, what error conditions exist (insufficient credit, invalid credentials, rate limits), and parameter semantics. Given the tool's complexity and the absence of output schema and schema descriptions, the description is materially incomplete for safe and correct agent 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 0% — the four parameters (instalacao, login_email, login_senha, login_empresa) have no schema-level descriptions. The tool description does not individually explain any parameter. It mentions 'pague por consulta' which implies login credentials are for the Enel CE service rather than the platform, but it never defines 'instalacao' (likely a utility installation/meter number) or clarifies credential provenance. With zero schema coverage, the description was required to carry this burden but did not, leaving the agent to guess at parameter semantics.

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 'Enel CE: Download, consulta em fonte oficial' — a verb+resource statement (download/query Enel CE data from an official source). It clearly distinguishes from the generic platform siblings (authenticate, connect, marketplace, etc.) as a domain-specific data retrieval tool for a Brazilian utility company. The verb and resource are specific, leaving no ambiguity about what this tool does.

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?

The description implies usage context: 'Hospedado pela plataforma, sem credenciais da plataforma' tells the agent that platform authentication is not needed, which implicitly signals not to use sibling 'authenticate'/'connect' first, and 'pague por consulta' states it's paid per query. However, there is no explicit 'when to use this vs. alternatives' guidance, no exclusions, and no mention of when a different tool would be more appropriate. It provides evident context but lacks explicit alternative mentions.

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