get_pixels

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuine behavioral detail about output shape (character rows + legend vs '#rrggbbaa' grid, transparency markers, indexed sprites returning palette indices), but says nothing about the maxPixels safety limit or failure conditions.

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?

Purpose is front-loaded in the first clause, and the format semantics follow in compact clauses. Every sentence carries information; the density is high with no filler.

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 correctly takes on the burden of describing return values, which it does for both formats and for indexed sprites. For a 7-parameter, all-optional read tool this is close to complete, with only the maxPixels limit behavior left implicit.

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 71%, and the description meaningfully extends the 'format' enum by explaining what each mode returns (legend characters plus color legend with '.' = transparent; hex grid with null = transparent). It also clarifies composited-frame vs single-layer reading, though it leaves rect, frame, backend, and maxPixels to the schema.

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 ('Reads') and resource ('pixels'), and scopes it to the rendered frame across all visible layers or a single layer. The read counterpart to draw_pixels is distinguishable from the verb alone, though no sibling is named explicitly.

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?

Implies the read use case and offers a scope choice (whole frame vs one layer), but gives no explicit when-to-use vs alternatives like draw_pixels, get_cels, or render_preview, and no exclusions or prerequisites.

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