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

The annotation readOnlyHint=false already signals mutation, and the description reinforces this with 'Update' while adding useful behavioral context: it returns 'its complete file, asset, and brand index'. This goes beyond the structured annotations, though it does not detail side effects or failure modes.

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 a single well-structured sentence, front-loaded with the action ('Update'), followed by the update targets and the promised return value. There is no filler or redundant wording.

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, no parameter descriptions, and only readOnlyHint=false, the description carries most of the burden. It gives a high-level purpose and return value but fails to explain required identifiers, brand color item format, or partial-update behavior, leaving the agent without enough information to construct a correct call.

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 0%, so the description must compensate. It mentions three updatable fields (name, description, brandColors) but omits the required workspaceProjectId and workspaceProjectKey, and does not explain the structure of brandColors items. This is insufficient for reliable invocation.

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 uses a specific verb ('Update'), identifies the resource ('marketing project'), and lists the updatable fields ('name, description, or named color scheme'). This clearly distinguishes it from sibling tools like picorn_projects_create and picorn_projects_inspect.

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 makes the context clear: use this tool to modify an existing project's name, description, or colors. It does not explicitly name alternatives or provide exclusion criteria, but the update semantics are obvious from the verb and resource.

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