Image Info

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 meaningful behavioral context beyond that: the tool intentionally avoids returning pixel data and instead reports metadata plus a tile grid recommendation. This tells the agent what side effects it avoids and what kind of result to expect.

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?

Two sentences, no filler. The first sentence defines the tool's core purpose and its key limitation, while the second sentence states the outputs. Every phrase contributes meaning, and the distinguishing 'without returning its pixels' is front-loaded.

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?

There is no output schema, so the description correctly takes responsibility for explaining what the tool returns: dimensions, bytes, and a recommended tile grid. Combined with the 100%-covered input schema and read-only annotations, an agent has enough information to invoke the tool correctly and interpret its result.

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 the schema fully documents path, tile_overlap, and workspace_id. The description mentions the tile grid concept, which loosely ties to tile_overlap, but adds little parameter-level detail beyond the schema. A baseline of 3 is appropriate when the schema already carries the parameter documentation burden.

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 a specific action, 'Inspect a workspace-local image', and clearly distinguishes the tool from siblings by saying it does not return pixels. It then names the concrete outputs: original dimensions/bytes and a recommended tile grid. This makes the tool's purpose unambiguous even before looking at the schema.

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 phrase 'for high-detail follow-up reads' gives clear context for when to use this tool. The negative statement 'without returning its pixels' implicitly tells the agent not to use it when pixel data is required, though it does not explicitly name read_image or read_image_crop as the pixel-returning alternatives. This is strong but not fully explicit.

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