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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, and the description adds meaningful context beyond those: the catalog is cached in memory, the result is limited to 10 documents, an empty list means no match, and results are relevance-ordered. There is no contradiction with annotations.

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 front-loaded with the core purpose and output contract, then adds routing guidance, query semantics, and behavioral notes. Every sentence carries distinct information, and there is no filler or redundant restatement of the tool title.

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 single-parameter search tool with a huge sibling set, the description is complete: it defines the search domain, output shape, max results, empty-list behavior, language/accent handling, read-only/idempotent behavior, and how to continue with `fetch` or switch to `senado_*` tools. The presence of an output schema also means return values do not need to be re-explained, yet the description still gives useful semantics.

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 coverage is 100% and the schema already documents natural-language/keyword search with accent/case insensitivity. The description adds value by explicitly stating that queries can be in Portuguese or English and by framing query construction more usefully for an agent, which goes beyond the baseline of simply repeating the schema.

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: 'Searches the Brazilian Federal Senate open data ... catalog' and states the exact output shape, result limit, and ordering. It also explicitly distinguishes itself from the senado_* data tools by identifying itself as a catalog index rather than a data query, so an agent can tell it apart from its many 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?

The description gives explicit routing guidance: use this tool for Deep Research catalog lookups and pass returned ids to `fetch`, while preferring `senado_*` tools for direct questions and actual data. This is concrete when-to-use and when-not-to-use guidance, directly addressing the large sibling list.

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