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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered. The description adds genuine value beyond that: the content shape of the return (name, arguments, meaning) and the session-scoping advice that the call is a one-time setup step. It does not mention catalogue size or pagination.

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 compact sentences, front-loaded with what the tool returns, followed by the one action directive. No filler or restatement of the tool name.

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, the description correctly describes the return content (name, arguments, meaning) and the call timing. It is nearly complete for a one-parameter read tool; only volume/pagination behavior is left unstated.

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 coverage is 100% and the single 'project' parameter is fully documented in the schema. The description only implies the project context via 'the open editor' and adds no syntax or format detail, so the schema does the heavy lifting.

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 and resource ('the full catalogue of ops the open editor can run') and enumerates the categories it covers (text, captions, trims, grading, sound, effects, AI tools). An agent can distinguish this from siblings like list_projects or list_media without opening the 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?

Gives explicit timing and ordering: 'Call once per session before edit_project,' naming the sibling that depends on it. It stops short of saying what happens if skipped or how to refresh the catalogue mid-session, so it is clear context rather than full when/when-not guidance.

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