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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavioral context not in the annotations: for HTML blocks it returns the full HTML plus 'what it keeps,' and for notes/shapes/frames it returns their fields. With no output schema, that disclosure is valuable.

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?

A single compact sentence with no filler, and the item-type return behavior is front-loaded. Slightly dense phrasing ('what it keeps') costs a little clarity but wastes no words.

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 item fetch with no output schema, the description usefully characterizes what comes back for each item type, and annotations carry the safety profile. Missing only error/permission behavior, which is minor here.

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 (boardId, blockId) are already documented in the schema, and the description adds no syntax, format, or constraint detail beyond that. Baseline 3 applies.

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 ('Read one item on a board') and scopes it to a single item, which implicitly separates it from the board-level read_board sibling. It stops short of naming read_board explicitly as the alternative, so the differentiation is inferable rather than stated.

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 only implied: 'one item' versus a board read suggests when to reach for this tool, and the schema notes the blockId comes from read_board, but the description itself gives no explicit when-to-use or when-not-to-use guidance.

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