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

The annotations already declare this as a safe read-only, idempotent operation, and the description adds the concrete return contract (`{ data, escopo, count, sessoes }`), the per-session fields, and the default-date/scope behavior. It goes well beyond the annotations without contradicting them, though it does not discuss pagination or error behavior, which are not critical here.

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 compact sentences cover purpose, return shape, scope usage, and sibling routing without repeating annotation or schema fields. The most important selection guidance is placed at the end but is still direct and economical.

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?

Given the rich output schema, fully documented parameters, and read-only annotations, the description supplies everything needed to select and call the tool correctly. It covers default behavior, scope options, return structure, and the two relevant sibling alternatives.

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?

The input schema already documents all three parameters at 100% coverage, including defaults, patterns, and enum meanings. The description only reinforces the `escopo` usage and the default `data` behavior rather than adding substantive new parameter-level semantics, so the schema-heavy baseline of 3 is appropriate.

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?

Opens with the verb 'Obtém' and identifies the exact resource: agenda de sessões de plenário, with variants for Senado and Congresso Nacional. It also names the scope dimensions (dia/mês) and the pauta contents, and the closing sentences distinguish it from the closest plenary siblings.

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 instructs which `escopo` values to use and states the default behavior when `data` is omitted. It also names concrete alternatives—`senado_resultado_plenario` for already-appreciated results and `senado_encontro_plenario` for session details—so an agent can route between siblings without ambiguity.

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