update_template

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

Annotations already declare destructiveHint=true and openWorldHint=true, so the mutation profile is known. The description still adds real behavioral context beyond them: that a non-existent page name is ADDED, an existing page has layers merged or replaced via replaceLayers, and that top-level width/height are rejected on multi-size templates. This goes meaningfully past the annotation set.

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?

One dense paragraph, front-loaded with the core action and then escalating to the non-obvious nested-schema rules. Every sentence carries a rule an agent would otherwise get wrong; there is mild redundancy with the schema descriptions but no 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 10-parameter nested mutation tool with no output schema and annotations already covering safety, the description covers the high-risk structural pitfalls (layer key naming, page add/merge/replace, multi-size size handling). It omits nothing critical, though it never mentions the required template_id or the effect on unspecified existing fields.

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 100%, so the baseline is 3, but the description contributes semantics not present in the schema: the merge-vs-add rule keyed on whether the page name already exists, and the routing rule between 'pages' and top-level 'layers'/width/height. It also reinforces the 'layer' vs 'name' key gotcha, which the schema states but which is easy to miss.

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?

Opens with a specific verb+resource ('Update an existing template'), which cleanly separates it from create_template, clone_template and delete_template in the sibling set. It does not explicitly name those siblings, but the verb distinction is unambiguous.

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?

There is no explicit statement of when to use update_template versus alternatives like clone_template or create_template, nor any prerequisite/permission guidance. The only conditional guidance ('for multi-page templates use pages', per-page width/height on multi-size templates) concerns parameter choice rather than tool selection, so usage context is implied at best.

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