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

Without annotations, the description carries full burden. It discloses that the tool is table-driven (not memory-based), requires rt_premium as input, and returns a detailed breakdown. It does not mention side effects or idempotency, but for a computation tool this is adequate. No contradictions.

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 concise (4 sentences) with no wasted words. It front-loads the main purpose and groups related information logically. Every sentence contributes meaning.

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 complexity (8 params, no output schema), the description provides a good overview: lists output fields, explains inputs, and notes table-driven logic. It could detail edge cases or calculation limits, but for a payroll tool it is fairly complete.

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%, so baseline is 3. The description adds value by explaining the purpose of SDI/SBC, the mutual exclusivity of seniority_years vs sdi, and the role of rt_premium. This goes beyond the schema descriptions, which are already good.

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 specifies the tool computes Mexican IMSS social-security contributions, lists specific outputs (SDI, SBC, employer/worker quotas, etc.), and the verb 'Compute' is precise. It distinguishes from sibling tools (calc_aguinaldo, etc.) by intent, though not explicitly. However, the purpose is unambiguous and specific.

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 clear input guidelines: provide either seniority_years or explicit sdi. It also warns against computing from memory (table-driven). However, it does not explicitly state when to use this tool versus alternatives (e.g., for ISR use calc_isr), though sibling names imply context.

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