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

Annotations already state read-only, idempotent, non-destructive and closed-world, so safety is covered. The description still adds real context beyond them: UK-first evidence scope, explicit exclusions (no terrain, 3D, DWG, desktop execution), what the response contains, and the rule not to reconstruct URLs or rerun source checks. Minor gap: it doesn't say what a failed or empty workspace state looks like.

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?

Labeled sections (Purpose / When to use / Returns / Limitations / Parameter guidance / Chaining) make it scannable and front-loaded. It runs long for a two-parameter tool, and the 'Purpose:' label restates the title, but no sentence is filler.

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?

For a nested site_ref parameter with an output schema present, the description covers everything an agent needs: entry-point routing, empty-argument behavior, prepared-result pass-through, limitations, and the site_ref chaining contract. Return values are delegated to the output schema, which is appropriate.

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 only 50%, and the undocumented parameter is compensated well: 'pass its exact details.widget_payload_url as prepared_result_url. Do not reconstruct a URL' explains the value's origin and a hard constraint the schema cannot express. The site_ref chaining guidance ('pass it unchanged') largely duplicates the rich schema description, keeping this from a 5.

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?

Names a specific verb and resource ('open Atlasly's interactive maps and site workspace') and immediately distinguishes itself from the long sibling list by saying to 'call the specific evidence tool directly for a specific question.' An agent can tell this is the entry/workspace tool rather than an analysis tool without opening any schema.

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?

Gives explicit when-to-use ('user wants to explore Atlasly tasks or open its workspace') and an explicit when-not with the alternative ('call the specific evidence tool directly for a specific question'). It also covers the ambiguous zero-argument case ('accepts empty arguments for exploration') and the prepared-result case.

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