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

The description adds substantial behavioral detail beyond annotations: server-side assembly, verbatim presentation requirement, rejection of forbidden territory (Ten Gods, strength, etc.), and client-side rendering guidance. Annotations already declare readOnlyHint and idempotentHint, and the description does not contradict them—it enriches them with concrete behavioral instructions.

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 long but every sentence serves a purpose: purpose, pipeline position, input requirements, presentation rules, and rejection behavior. It is front-loaded with the core purpose. No filler; each clause carries actionable info. It could be tightened slightly but is well-structured for an agent.

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?

The tool is complex (step 2 with rejection and presentation rules), and the description covers all necessary aspects: what to submit, what happens server-side, how to present the result, and error handling. With an output schema present, return values are already documented. The description is complete enough for an agent to invoke correctly without ambiguity.

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%, so the baseline is 3. The description adds value by requiring the three sections be in the same language as the conversation and clarifying that they originate from the prior step. It also hints at content constraints (forbidden territory) that affect what values are acceptable, which goes beyond the raw schema descriptions.

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 clearly states it is step 2 of 2 for a personality sketch, specifying the exact inputs (image, beneath, practice) and the output (a finished framed sheet with server-side assembly). It distinguishes itself from siblings by noting it follows personality_sketch and is distinct from cast_chart, which is a different workflow. The verb 'compose' and resource are concrete and unambiguous.

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?

It explicitly positions itself as step 2 after personality_sketch, instructing the agent to submit sections written in that step, and gives clear presentation instructions (verbatim, no edits) and a rewrite/resubmit flow on rejection. It does not explicitly name alternative tools or say 'when not to use', but the pipeline step is unambiguous. The guidance is strong enough for correct selection.

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