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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=true, idempotentHint=true, openWorldHint=true) by disclosing the webhook side effect ('fires the template.updated webhook'), the return payload, the partial-update semantics ('replacing only the fields given'), and a hard scope limit ('cannot move the preset to another project'). No contradiction with destructiveHint, since sizes/formats replace the prior list.

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 dense sentences: trigger and scope first, side effects and constraints second. The mention of the return value is mildly redundant with the output schema but costs only a clause and reinforces the partial-update behavior.

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 four-parameter mutation with full schema coverage, an output schema, and safety annotations, the description supplies everything else an agent needs: the webhook side effect, the partial-replace semantics, and the project-move limitation.

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 names the updatable fields but adds no syntax, constraints, or format detail beyond what the schema already documents for name, sizes, formats and templateIdOrName.

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+resource ('update ... fields on one existing Imagelato resize preset'), names the exact fields touched (name, output-format, width), and explicitly excludes the create case, which separates it from add_template. An agent can distinguish it from every sibling without opening a 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?

Opens with an explicit trigger ('Use this when the user wants to update...') and adds a negative boundary ('Not for creating a preset'). It does not name add_template as the alternative, but the exclusion is unambiguous enough for correct routing.

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