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

Annotations only say readOnlyHint=false, idempotentHint=true, destructiveHint=false; the description adds genuinely new behavioral facts — FREE/no credits, creates nothing new, image is queued into the board inbox and materializes asynchronously the next time Canvas is open. That async caveat plus the instruction not to claim it is on screen is exactly the context annotations cannot convey.

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?

Front-loads the core action, then constraints, then cost, then the async caveat and user-facing instruction. Dense but every sentence carries an operational fact; nothing is filler.

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?

Complete for a zero-required-param mutation with no output schema: it covers cost, idempotency implications, accepted inputs, refusal cases, delivery timing, and what to tell the user. An agent can call this and set expectations correctly with no further lookup.

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%, and the schema already documents the either/or rule for url vs historyId and the 'omit to let whichever board opens first claim it' behavior for projectId. The description mostly restates this; its only marginal addition is reiterating that url must be an AIGE storage host, which the schema also states.

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 (place/send) and resource (image onto AIGE Canvas board) with scope: 'an image this user ALREADY generated in AIGE'. It distinguishes itself from sibling generation tools by emphasizing it creates nothing new and moves existing output, so an agent can tell it apart from antix_generate_image or the deck tools.

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?

Explicit conditions and exclusions: pass EITHER historyId (from antix_get_history) OR url, never both; images only; video generations and non-AIGE-host URLs (including expiring provider links) are refused. It also names the upstream tool that supplies the id, which routes the agent correctly.

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