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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds useful behavioral context beyond the annotations: what the tool returns (full content, section structure, metadata) and the optional section-scoped read mode. It does not cover failure behavior or restrictions, but annotations cover the safety profile well.

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 three sentences, front-loaded with the core purpose, and contains no filler. Every sentence contributes either the return shape, the optional section mode, or parameter sourcing guidance.

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?

With no output schema, the description covers the return values sufficiently (full content, sections, metadata). It also explains how to obtain section IDs and slugs, which is important in a tool ecosystem with many siblings. It does not clarify run_id's role, but the schema fully describes that parameter.

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. The description adds meaningful guidance: using get_canvas_toc to discover section IDs, using list_canvas to find slugs, and passing playbook_id as UUID/GUID. These references enrich the schema descriptions and help agents source correct parameter values.

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 clearly states the tool reads a canvas document, returns full content, section structure, and metadata, and supports optional section-level reads. This distinguishes it from siblings like get_canvas_toc and list_canvas, which are explicitly positioned as discovery helpers.

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 usage—read a canvas when you need full content or a specific section—and gives guidance for using get_canvas_toc to find section IDs and list_canvas to find slugs. However, it does not explicitly state when to prefer read_canvas over these sibling tools or when not to use it.

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