lookup_pipe_diameters

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 what the tool returns (a table of standard sizes with four columns), the material standards (e.g., HDPE PE100, PVC AWWA C900), and filter options. It implies a read-only lookup operation, though it doesn't explicitly state that it has no side effects—but for a lookup tool that's inferable.

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 information-dense but not overly long. It front-loads the purpose, then lists materials and filtering options, and ends with use cases. Each sentence adds value, and the structure is logical. It could be slightly more concise but is well organized.

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 (four parameters, multiple material standards, no output schema), the description covers the return format, material options, filter behavior, and use cases. It does not provide an example output or mention edge cases like units for steel inputs, but it is sufficient for an agent to call the tool correctly.

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 meaning beyond the schema by explaining that nominal sizes always show their native designation, that units default to 'mm', and that min/max filters can be omitted for all sizes. It also clarifies the material enum values with standards, enriching the schema definitions.

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 states the specific verb 'look up' and the resource 'standard pipe inner diameters for common water-distribution materials', and clarifies it returns a table with nominal, outer, wall thickness, and inner diameters. It distinguishes from siblings like pipe_sizing_wizard by focusing on standard size lookup rather than computation.

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 explicitly says 'Use this when sizing pipes, choosing a standard diameter for set_pipe_diameter, or comparing materials for a given nominal size.' It gives clear when-to-use contexts but does not contrast with alternative tools or mention when not to use it, so it falls short of a 5.

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