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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds value annotations cannot express: that reads are free ("Cost: Free") and that the start guide is a one-time read rather than something to re-fetch — genuine behavioral context for an agent managing context budget.

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 short clauses, zero filler, and the highest-value instruction (read start once) is front-loaded. The telegraphic style means it reads as notes rather than prose, but nothing is wasted.

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 values need not be described, and the single parameter is fully documented in the schema. The description covers the cost model and the two highest-stakes reads; the only real gap is that an agent gets no signal about what the remaining topics contain or when to prefer them.

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 enum already documents every topic plus the default ("start when left out"), so the schema carries most of the weight. The description adds meaning for only two of the fifteen enum values (start, graphics), leaving the rest of the topic taxonomy unexplained beyond their labels.

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?

"Editing guide." names the resource but supplies no verb of its own — the action (read) only arrives via the title. It is enough to tell this apart from write_graphic and the get_* data tools, but the purpose statement itself is a noun fragment rather than a specific verb+resource claim.

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?

"Read start once, and graphics before write_graphic" gives concrete when-to-use guidance, including an explicit sequencing precondition tied to a named sibling tool. It stops short of explaining when to consult the other twelve topics (canvas, captions, sound, voice, motion, etc.), so coverage is partial rather than exhaustive.

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