Replace website PHP extensions

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

The description reveals the destructive behavior: 'Any toggleable extension not in the request is disabled', and clarifies built-in extensions are 'always active and are unaffected'. This goes well beyond the annotations (idempotentHint, destructiveHint), adding concrete operational consequences.

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?

Three sentences, no filler; the core action is first, with essential warnings and exceptions following. Each sentence carries necessary information.

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?

With only two parameters and annotations covering safety, the description supplies all needed operational context: full-set semantics, built-in exception, and endpoint ordering. No output schema exists so return values need not be documented.

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 already covers both parameters at 100%. The description adds meaning to the extensions parameter by requiring the full desired set and explaining the toggleable/built-in distinction, which is beyond schema text.

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 names the verb ('Replaces'), resource ('set of PHP extensions enabled on an Agency Plan website'), and effect ('with the ones provided'). It clearly differentiates from sibling listing/reset tools by emphasizing replacement semantics.

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 instructs the caller to 'call the extensions endpoint first and send the full desired set', which is direct procedural guidance. However, it does not explicitly name alternative tools or exclusion conditions, so 4 rather than 5.

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