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

With no annotations, the description bears full responsibility for disclosing behavior. It does not state whether the tool is read-only, what happens with invalid inputs (e.g., numbers outside the stated range), or any rate limits or prerequisites. The behavioral profile is under-specified.

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?

A single sentence that efficiently conveys the core function and parameter constraints. No extraneous words, and critical information (number range) is front-loaded.

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?

The tool is simple (2 params, no output schema, no annotations), so the description covers the bare essentials: purpose and parameter constraints. However, it fails to describe the return format or behavior on error, which leaves gaps for an agent expecting a complete specification.

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 schema provides integer parameters with no descriptions (0% coverage). The description adds meaning by specifying they are Life Path numbers and restricting to 1–9 or master numbers 11/22/33. However, it doesn't clarify required positivity or error handling for invalid inputs, so only partial compensation.

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 it computes numerology compatibility between two Life Path numbers, specifying the valid range (1–9 or master 11/22/33). This distinguishes it from sibling tools like life_path (computes a single number) and numerology_profile (provides full profile). However, it does not explicitly state what the output is (e.g., score, rating, text), which slightly dims clarity.

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?

No guidance is provided on when to use this tool versus alternatives. For example, it does not mention that life_path should be used first to calculate a user's life path number before using compatibility, nor does it compare with name_numbers. The agent is left to infer usage context.

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