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

Goes beyond the annotations by disclosing that the operation is reversible ('Reversible by calling it again with the old value') and that it is 'free of any plan check' — both are non-obvious behavioral traits for a write tool that the destructiveHint=false annotation alone does not convey. It does not describe permissions or what the response returns.

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?

Three sentences, no filler: capability list first, sibling exclusion second, reversibility/cost third. Every sentence carries information an agent needs.

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?

Covers scope, the sibling boundary, reversibility and the absence of a plan gate for a mutation tool with no output schema. The main omission is any mention of required permissions or account-scope preconditions, which an agent may need to call this correctly.

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, but the description maps each capability to a parameter (rename, reassign account, change re-entry behavior), adding intent-level meaning on top of the already detailed schema text. The instagramAccountId=null semantics are left entirely to the schema.

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 precise verb set and resource ('Renames a DM flow, moves it to a different connected Instagram account, or changes what happens when somebody triggers it a second time') and explicitly disambiguates from the sibling flows_set_steps. An agent can distinguish it from flows_create, flows_pause or flows_set_steps without opening any 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?

Explicitly routes step-editing work to flows_set_steps ('It does not change the flow's steps'), which is a clear when-not-this-tool rule. It gives no guidance on ordering versus flows_publish or flows_create, but the primary boundary with the closest sibling is stated.

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