append_site_custom_code

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

Annotations provide only readOnlyHint=false, so the description carries most of the burden. It usefully discloses that this is an additive, non-read-first mutation in contrast to a full rewrite, which is genuine behavioral context, but it omits permission requirements and what happens if the target field is empty or missing.

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 short sentences, each earning its place, with the core additive behavior front-loaded before the alternative-tool pointer. No redundancy or padding.

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 3-param mutation tool with no output schema, the description covers purpose, usage, and the sibling alternative well. It stops short of stating return behavior or edge cases, but nothing critical for correct invocation is missing.

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%, so field, code, and position are already fully documented. The description reinforces the append/prepend distinction and the kinds of code supported but adds no syntax or format detail beyond the schema. Baseline 3 applies.

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?

States a specific verb pair (append/prepend) and resource (custom code field) with clear scope, and explicitly contrasts with the sibling update_site_custom_code. An agent can distinguish it from the update and get variants without opening a 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 an explicit when-to-use condition (adding new CSS rules, JS, script tags) and names the alternative (update_site_custom_code) for the opposite case (full rewrites). Both the trigger and the exclusion are present.

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