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

Annotations already declare readOnlyHint=true, destructiveHint=false, so the safety profile is covered. The description adds real value beyond them: grant lifecycle is user-managed in-app, and the call predicts immediate placement vs. approval-link flow. The only omission is that idempotentHint=false is unexplained for what reads like a pure read.

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 sentences, front-loaded with what the tool returns and then the reason to call it. The first sentence is a long field list, but every item is meaningful payload disclosure in the absence of an output schema. Little waste overall.

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?

With no output schema, the description takes on the job of explaining return values and does so thoroughly (wallet, caps, remaining today, order kinds, signer status). Combined with the usage trigger, an agent has everything needed to call and interpret it.

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?

Zero parameters, so the schema carries no semantic burden and the baseline is 4. The description adds no parameter detail because none is needed, though it does imply the channel context is derived from the session rather than passed in.

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 and resource ('the signed-in account's agent grant for this channel') and then enumerates exactly what the grant object contains (wallet, per-order and daily caps, remaining today, allowed order kinds, signer status). This is unmistakably distinct from the sibling get_me, get_approval, and the place_* 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?

Gives explicit timing ('Call it before placing') plus the decision it enables (whether an order will be placed immediately or need an approval link), and names get_approval implicitly by referencing the approval path. It also clarifies the alternative to mutation: grants are created and revoked by the user in the app, never by a tool.

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