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

Adds real context beyond annotations: the call may activate the permission only after successful setup and ownership checks, and never charges a card — resolving the main ambiguity of a mutating call in a payments system. However, annotations declare idempotentHint=false and the description says nothing about retry safety or what happens if the ownership check fails, which is the key remaining behavioral gap for a non-idempotent mutation.

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 tight sentences ordered trigger → mechanism → exclusions, with zero restatement of the name or title. Every sentence carries routing or safety information.

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?

For a one-parameter mutation with no output schema, the description covers trigger, prerequisite, effect (permission activation only, no charge), and alternatives. It stops short of describing failure behavior or the safe retry path implied by non-idempotency, which would fully close the loop.

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 single parameter already carries a description pointing at create_card_authorization, so the schema does the heavy lifting. The description restates the same provenance hint plus a 'for this machine' scoping note, adding marginal value rather than new syntax or format detail.

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?

Specific verb ('reconcile') plus resource ('saved-card authorization with Stripe') plus the precise trigger ('after completing a Stripe SetupIntent with Stripe.js'). It explicitly names the two siblings it is not (create_card_authorization, sync_card_payment), so an agent can route correctly 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?

Gives the precondition (SetupIntent completed via Stripe.js), the required input provenance (authorization_id from create_card_authorization), and two explicit exclusions with the alternative tool named for each. No inference is required to choose between this and its siblings.

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