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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered without the description. The description adds the page size ('25 per page by default') and the returned field set, but says nothing about rate limits, auth requirements, or ordering. That is modest added context on top of comprehensive annotations.

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 short sentences, front-loaded with the usage trigger followed by scope, return shape and exclusion. No filler or redundancy.

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, zero-required-parameter list tool with an output schema, this covers purpose, scope, pagination and exclusion adequately; return-field detail is arguably redundant given the output schema. A model would still lack guidance on ordering or cursor invalidation, but nothing critical is missing.

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 limit, cursor and projectId are each documented in the schema itself; baseline is 3. The description only restates project scoping and the default page size, adding no format or syntax detail beyond 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 ('list existing Imagelato resize and format presets') plus scope ('optionally scoped to one project'), and explicitly excludes the adjacent entity ('Not for the images processed with them'). An agent can distinguish this from list_projects, list_batches, or list_webhook_subscriptions without opening any 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 an explicit trigger ('Use this when the user wants to list existing... presets') and an explicit exclusion ('Not for the images processed with them'). It stops short of naming the alternative tool for listing processed images, so the routing guidance is clear but not complete.

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