List PHP extensions for a website

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

Annotations already provide readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds value by specifying that it returns 'every' extension and includes enabled status, but it does not disclose additional behavioral details such as failure modes or permission requirements. This is adequate but not rich.

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, well-structured sentence that states the action, scope, and return details with no filler. The key scoping phrase 'Agency Plan website' is front-loaded, and every word contributes to understanding.

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 simple read-only list operation with one documented parameter and no output schema, the description is sufficient. It explains what is listed, for what scope, and what status information is included. The safety profile is already carried by the annotations.

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%: the only parameter, website_uid, is described as 'Agency Plan website UID'. The description does not add parameter-specific meaning, but with full schema coverage, the baseline of 3 is appropriate.

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 uses a specific verb ('Lists'), a clear resource ('every PHP extension available to an Agency Plan website'), and a meaningful detail ('whether it is currently enabled'). It immediately distinguishes itself from sibling tools like agency-hosting_replaceWebsitePHPExtensionsV1 and agency-hosting_listAvailablePHPVersionsForAWebsiteV1.

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 clearly identifies the context: use it for an Agency Plan website when you need to inspect available PHP extensions and their enabled state. It does not explicitly name alternatives or exclusions, but the Agency Plan scope is a clear contextual marker relative to the many hosting and VPS siblings.

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