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

Annotations only declare readOnlyHint/openWorldHint; the description adds ordering (most recent first), scope exclusion (personal library only, no workspace/shared assets), and the behavioral trait that each item carries a reusable url. This cross-tool reuse semantic is context the structured fields do not provide.

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?

Front-loaded with purpose, then filters, then the high-value reuse tip, then sibling differentiation — each sentence earns its place. It is dense and runs long for a single paragraph, but there is 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?

For a read-only filtered-list tool with no output schema, the description covers scope, ordering, filters, pagination, and even the practical downstream use of the returned url. Combined with readOnly annotations, an agent has everything needed to call it correctly.

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 baseline is 3; the description reinforces the defaults (limit default 20, max 50) and clarifies source semantics. It goes beyond the schema by explaining what the returned url field enables, though the four input parameters themselves are already fully documented in 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 and resource ('browse the current user's saved Popcraft media library') plus scope details (uploaded/imported vs generated outputs, sorted most recent first). It also explicitly contrasts itself with the sibling 'popcraft_show_generations' (job history vs persisted asset library), so an agent can disambiguate without opening either 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?

Gives explicit when-to-use ('find media the user already has rather than asking them to re-upload') and when-to-use-the-other ('For the history of generation JOBS ... use popcraft_show_generations'). It also documents the filter conditions (type/source) and pagination controls, leaving nothing to inference.

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