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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the agent knows this is a bounded, non-destructive mutation. The description adds no behavioral context beyond that: it does not say whether existing clips are reframed, whether a change is undoable, or what happens to text/positions when the canvas changes (the 'reframe' behavior lives only in the schema). The platform hints (Reels/TikTok/Shorts) are orientation help, not behavior disclosure.

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 sentence that front-loads the rename action and then lists the canvas settings, with zero filler. The parenthetical platform examples are the only mild clutter, though they do add selection value.

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 an 8-parameter mutation tool with no output schema and thin schema descriptions, the description covers the main mutable fields but omits the aspect-vs-width/height precedence rule and any statement of the effect on existing content. An agent could still call it correctly, but would be guessing on conflicts and side effects.

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 25% (only reframe and projectId are documented in-schema), so the description must compensate and largely does: it maps rename→name, fps, background, and both the aspect enum presets and width/height. It adds platform-use meaning for 9:16 that the enum alone does not convey. Only the interaction between aspect and width/height is left ambiguous.

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 opens with a specific verb and resource ('Rename the project or change canvas') and enumerates the exact settings that are mutated: aspect preset, width/height, fps, background color. It is clearly distinct from the neighboring brand/cover tools. It stops short of naming a sibling it is not, so it is a strong 4 rather than a 5.

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 phrase 'aspect preset ... or exact width/height' implicitly tells the agent these are two alternative ways to set the frame, which is useful routing information. However, there is no explicit statement of when to prefer preset over explicit dimensions, no mention of conflicts when both are supplied (aspect enum includes 4:3/21:9 not listed in the description), and no prerequisites or when-not-to-use guidance.

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