Generate Media Contact Sheet

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

Annotations only declare readOnly=false, destructive=false, idempotent=false and openWorld=false. The description adds real value beyond them: the output is disk-verified, it refuses to overwrite an existing file, and it does not modify Premiere or the source media, clarifying where side effects land. It stops short of stating failure modes for unsupported inputs or runtime prerequisites.

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 tight sentences, front-loaded with the artifact produced and then the key behavioral constraints. No filler, no repetition of schema or annotation content.

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?

An output schema exists, so return-value explanation is not needed, and the description covers the material behavior (creates new file, no overwrite, doesn't touch source/Premiere). Slightly short on edge cases like invalid ranges or media that can't be decoded, but overall adequate for a 5-param tool.

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 100%, so rows, columns, thumbnail_width, media_path and output_path are already fully documented with ranges and defaults. The description adds only the 'evenly sampled source frames' hint about how sampling works, not per-parameter meaning, so the baseline 3 applies.

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 (Generate) plus resource (a PNG contact sheet from evenly sampled source frames), which clearly distinguishes it from frame-oriented siblings like export_frame or export_sequence_review_frames. The scoping phrase 'disk-verified' and 'evenly sampled' pins down what artifact is produced.

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?

Usage is implied by the description (create a contact sheet artifact), and the no-overwrite constraint gives a practical precondition. However it never states when to prefer this over alternatives such as export_frame or the review-frame exporters, and gives no exclusion guidance.

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