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

Annotations already declare readOnlyHint=true. The description adds behavioral context: 'Serves published measured figures only' indicates no real-time computation, and 'Fuzzy destination filter' indicates matching behavior. This goes beyond annotations with useful details.

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 brief and front-loaded with key information. No redundant sentences, but structure is somewhat fragmented (uses incomplete phrases like 'Serves published measured figures only.') that could be clearer.

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 no output schema, the description provides units of measure (km, minutes) but does not specify the return format (list vs. single value) or how results are structured. It covers the core functionality but lacks detail on response shape.

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 0%, so the description must compensate. It explains the 'property' and 'destination' parameters implicitly (property as origin, destination as fuzzy target), but 'town' is not explained. Lack of clarity on parameter roles and constraints reduces utility.

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?

Description clearly identifies the tool's purpose: measuring distances from a property to various points of interest like hospitals, mines, airports. It specifies units (km, drive/walk minutes) and mentions fuzzy destination filtering. However, it does not explicitly differentiate from sibling tools, though the context suggests it is unique.

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 implies usage when distances to fuzzy destinations are needed, but does not provide explicit when-to-use or when-not-to-use guidance. It does not mention alternatives among siblings, though the context signals help.

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