layer

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

With no annotations, the description carries the behavioral burden and does disclose the important conventions: north is up, x runs right, y counts from the bottom, letters are blocks and '.' is air. That is meaningful context an agent cannot get from the bare schema. It does not state whether the operation is read-only, though "checking" implies it, and the output form is partly covered by the output schema.

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 dense sentence with the orientation convention front-loaded and no filler. The grammar is slightly compressed ("a letter a block"), but every clause carries information.

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 two-parameter read tool with no annotations and an output schema, the description covers the output semantics well but leaves the 'design' input unexplained and never explicitly confirms the operation is side-effect free. Adequate, with a clear remaining gap.

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%, so the description must compensate for both parameters. It clarifies the 'y' parameter's origin ("y counted from the bottom"), which is genuinely useful, but says nothing about 'design' — whether it is a name, id, or handle, or how to obtain one. Half the parameters remain opaque.

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 states concretely what is produced: one horizontal slice of the design rendered as text, with orientation and glyph legend. It implicitly distinguishes from the whole-view 'preview' sibling, though it never names it. The phrasing is cryptic but the resource and output form are unmistakable.

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?

"For checking exact positions" gives an intended use case, which is real guidance. However it names no alternative (e.g. preview for a full view, box/line for bulk edits) and states no when-not conditions, so the agent must infer when a single-layer dump beats other inspection tools.

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