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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), so the bar is lower. The description still adds two non-schema facts: the call is 'Free' (cost behavior) and it 'Returns its id' (result side, which matters because no output schema exists). It does not cover auth requirements or whether repeated names create duplicates, so it stops short of a 5.

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, front-loaded sentences: trigger, return value, exclusion. No filler, no repetition of the title, and the most decision-relevant information (when to use it) comes first.

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 single-parameter create tool with no output schema, the description covers the trigger, the negative case, the cost, and the return value. Annotations cover the mutation/safety profile, so nothing an agent needs to call this correctly 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% for the single parameter, including examples ('Q4 launch', 'Client: Glow Skincare'), so the schema already carries the semantics. The description adds nothing about the name beyond what the schema states; baseline 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?

States a specific verb and resource ('Create a canvas' / 'a new, separate XcutAI canvas') and scopes the use case to a project, client or campaign. It also implicitly distinguishes itself from the read siblings by noting that import/write tools pick a canvas automatically, so an agent can tell it apart from xcut_get_canvas, xcut_list_canvases, xcut_import_post and xcut_write_content.

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?

Explicitly gives the triggering condition ('when the user asks for a new, separate ... canvas for a project, client or campaign') and an exclusion ('Do not use just to import or write: those tools pick a canvas automatically'). This routes the agent away from the import_* and write_* siblings without needing to open their schemas.

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