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

Annotations already carry the full safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lowered. The description adds genuine value with the pagination contract ('cursor = the previous next_cursor while has_more') and the note that web-app-created images are included, but it says nothing about ordering stability, freshness/eventual consistency, or result caps beyond the schema's limit.

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?

Three compact fragments, front-loaded with scope and ordering before usage guidance — zero filler. The telegraphic style ('while has_more', 'To let them CHOOSE one') is efficient but slightly clipped, costing a bit of readability.

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 still surfaces the key response fields an agent must handle (`url`, `next_cursor`, `has_more`), which is exactly what's needed for a paginated list. The omission is the undocumented `status` filter, leaving one of three parameters unexplained end-to-end.

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 67% and both documented params restate what the schema already says; the description's cursor explanation is a near-duplicate of the schema text. The `status` filter has no description in either place beyond the single-value enum, and the description never mentions it. Baseline 3 fits for a schema that does most of the work with one unexplained param.

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 opener names the resource (the account's images), the scope (web app included), and the ordering (newest first), which is enough to distinguish it from get_image (single item) and show_images (interactive chooser). It never states the verb explicitly, but the 'newest first' + paging framing makes the list semantics unambiguous.

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?

It gives an explicit WHEN clause ('the user asks what they made, or you need an earlier image's url') and names the alternative for a different intent ('To let them CHOOSE one: show_images'). An agent can route correctly without inspecting any schema.

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