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

The description adds substantial behavioral context beyond the annotations: England-only coverage, 250-1000m radius, encoded-request versus rendered-geometry caveats, metadata-planned layers not being render acceptance, sample counts, unknown failures, and verification needs. It also notes no separate H3 density fetch or cache write, which is useful side-effect context.

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 well structured and front-loaded with Purpose and When to use, and the limitations are valuable rather than filler. It is somewhat long and includes a Returns section despite the presence of an output schema, plus parameter guidance that partly duplicates the schema.

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, nested site_ref object, and existing output schema, the description provides enough context to call it correctly. It covers scope, alternatives, limitations, parameter expectations, and chaining behavior without needing to explain the output schema.

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%, and the description's parameter guidance largely restates the existing schema: address, optional layers, radius_meters, and title. It does reinforce chaining via site_ref, but that is also already documented in the site_ref schema description, so the added parameter meaning is limited.

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 a specific verb and resource: composing Atlasly source-backed site layers into one shareable map URL. It explicitly distinguishes this from get_map_layer_plan when the user only needs machine-readable layer actions.

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?

It gives an explicit when-to-use condition based on the user wanting a single map with flood, heritage, planning history, transport, constraints, or precedent layers. It also names the alternative tool and the exact condition selecting that alternative.

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