AEAT MCP Server

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

No annotations are provided, so the description carries the full burden. It discloses the return format (casilla number, name, section, and source article) and the data source (AEAT Manual Practico Renta 2025), but lacks details on error handling, rate limits, or authentication needs, which are important for a search tool.

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, followed by usage examples and return details, all in three efficient sentences with zero waste. Each sentence adds necessary context without redundancy.

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 tool's moderate complexity (search with one parameter), no annotations, and no output schema, the description is fairly complete—it covers purpose, usage, and return format. However, it could improve by detailing error cases or limitations, such as handling of partial matches or case sensitivity.

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 100%, so the schema already documents the query parameter with examples. The description adds marginal value by reinforcing the same examples but does not provide additional semantics beyond what the schema offers, such as query formatting rules or search behavior nuances.

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 clearly states the tool searches the Modelo 100 (IRPF) casilla map by number or keyword, specifying the exact resource and operation. It distinguishes itself from siblings by focusing on casilla definitions rather than deductions, brackets, or other tax-related data.

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 provides clear context on when to use this tool (searching casillas by number or keyword) with examples, but does not explicitly state when not to use it or mention alternatives among the sibling tools, such as get_tax_form_info or search_tax_rules, which might overlap.

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