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

With no annotations, the description carries the full behavioral burden, yet it only says 'Update.' It does not disclose whether omitted optional fields are preserved or reset, whether the change is reversible/undoable, what editor state or permissions are required, or what is returned.

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?

A single tight, front-loaded sentence with zero waste. However, for a 20-parameter mutation tool the brevity leaves it under-specified rather than genuinely concise.

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?

Given 20 parameters, no annotations, no output schema, and 30% schema coverage, the description is far too thin. It omits partial-update semantics, editor-state prerequisites, and any return/effect information an agent needs to invoke 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 only 30%, so the schema leaves most of the 20 parameters undocumented. The description supplies no parameter meaning at all, failing to compensate for the coverage gap (e.g., align, content, rotation, fontWeight, borderColor are defined nowhere).

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 a text layer on a screenshot in the open editor.' This distinguishes it from sibling update_div and update_asset, which target other element types. It is clear what it does, though it does not explicitly contrast with add_text.

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?

No explicit when-to-use guidance or named alternatives. The agent must infer that this modifies existing text layers while add_text creates them, and that the editor must be open. No conditions or exclusions are stated.

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