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

No annotations are provided, so the description carries the full burden. It discloses that the tool returns metadata including dimensions, format, paths, and CDN URLs, which adds behavioral context beyond the basic read operation. However, it doesn't mention potential errors (e.g., invalid ID), rate limits, or authentication needs, leaving some gaps.

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 two sentences, front-loaded with the core purpose and followed by specifics on return values. Every sentence adds value without repetition, making it efficient and well-structured for quick understanding.

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?

Given the tool's low complexity (single parameter, no output schema, no annotations), the description is fairly complete: it states purpose, usage context, and return details. However, without annotations or output schema, it could benefit from mentioning error cases or exact return structure, but it's adequate for a simple read tool.

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 already documents the 'id' parameter fully. The description adds no additional parameter semantics beyond implying it's for a specific image, which is redundant with the schema. With high coverage, the baseline is 3, but the description is concise and doesn't mislead, so a 4 is appropriate for not adding unnecessary detail.

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 verb ('Get') and resource ('detailed metadata for a specific image by its ID'), specifying it returns full image information. It distinguishes from siblings like 'list_images' (which lists multiple) and 'get_cdn_url' (which focuses only on URLs).

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 context by specifying 'by its ID' and listing returned details, suggesting it's for retrieving metadata of a known image. However, it doesn't explicitly state when to use alternatives like 'search_images' for unknown IDs or 'get_cdn_url' for just URLs, though the distinction is clear from the purpose.

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