comp_update_text

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does disclose the partial-update behavior ('only supplied fields'), which is valuable. However, it doesn't disclose whether the update is destructive to unspecified fields (it implies it isn't), whether it requires the comp to be in a certain state, or what happens if the text_id doesn't exist. The description is honest but minimal.

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, efficient sentence that front-loads the key behavior ('Update only supplied fields') before naming the resource. Every word earns its place, and there's no fluff. It could arguably add more detail, but for what it says, it's concise and well-structured.

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 tool with 13 parameters, 0% schema description coverage, no annotations, and no output schema, the description is far too thin. An agent would not know what fields are available, what the defaults mean, how the positioning fields (x_pct, y_pct, w_pct) interact, or what the return value looks like. The partial-update behavior is helpful, but the overall context is incomplete for correct invocation.

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 for the 13 parameters. It does not. The description only says 'supplied fields' without listing or explaining any of the parameters (text, align, color, start, w_pct, x_pct, y_pct, bg_color, duration, font_family, font_size_px). The schema provides types and defaults, but the description adds no semantic meaning about what these fields do or how they relate to each other.

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 'Update only supplied fields of a text overlay' clearly identifies the verb (update), the resource (text overlay), and the key behavioral nuance (only supplied fields are updated, implying a partial update rather than a full replacement). It distinguishes itself from comp_add_text (which creates) and comp_remove_text (which deletes), though it doesn't explicitly name those siblings.

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 implies usage context: it's for updating an existing text overlay, and the 'only supplied fields' phrasing signals that omitted fields are preserved. However, it doesn't explicitly state when to use this tool versus comp_add_text or comp_remove_text, nor does it mention any prerequisites like the overlay needing to exist or the comp needing to be valid.

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