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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context beyond annotations: it reports active frameCount and lastChangedAt, distinguishes empty from populated pages, describes ambiguous-page error behavior, and states the project:read scope.

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 front-loaded with the core action and then layers on return details, error behavior, and scope. It is dense but structured, with little obvious waste, though the final scope sentence and the frame-resolution aside could be slightly tighter.

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 read-only list tool with two optional parameters and full schema coverage, the description is largely complete: it covers what is returned, how empty pages are distinguished, and how page resolution errors behave. It stops short of describing pagination or exact response shape, but no output schema exists and those gaps are minor.

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 both parameters are already documented in the schema. The description adds some meaning around page hierarchy and branch derivation, but it does not elaborate on limit semantics or add syntax beyond what the schema already provides; 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?

The description uses a specific verb and resource ('List pages') and narrows scope to the branch's project, including subpages via parentCanvasPageId. It also distinguishes itself from frame-oriented operations by noting that frame-addressed operations resolve pages automatically, so an agent can tell it apart from list_canvas_frames.

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?

Usage is implied rather than stated: the description explains that existing frame-addressed operations resolve their page automatically and that ambiguous page errors enumerate candidates, which helps an agent understand when this tool is necessary. However, it never explicitly says when to use list_canvas_pages versus list_canvas_frames or list_recent_canvas_changes.

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