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

Annotations already mark the operation as non-read-only and non-destructive, and the description adds useful context about plan limits and capturing existing styling/media. It does not disclose behaviors like failure when expected_revision is stale or what happens if plan capacity is exceeded, but the annotations lower the burden.

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?

The description is a single front-loaded sentence with no filler. Every phrase, including 'existing styling and media', 'as a theme', and 'within the limit of the plan', contributes meaning.

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 mutation tool with 3 required parameters, no parameter descriptions, and no output schema, the description leaves a critical unknown (expected_revision) and gives no sense of return values or plan-limit behavior. It is not complete enough for an agent to construct a correct call confidently.

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 0%, and the description only indirectly clarifies catalogue_id (the catalogue whose styling/media is saved) and possibly name (the resulting theme's name). expected_revision is completely unexplained despite being required with a 64-character hex pattern, so the description does not compensate for the schema's lack of parameter documentation.

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 ('Saves') and resource ('existing styling and media of the catalogue') and clearly frames the result as a theme. It distinguishes from likely siblings like apply_theme and update_theme by emphasizing creation from a catalogue, though it does not explicitly name those alternatives.

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 implies the intended scenario: you have a catalogue whose current styling/media you want to preserve as a theme, subject to plan limits. It gives no explicit guidance about when to use this tool versus apply_theme or update_theme, leaving the agent to infer selection from the title and verb.

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