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

With no annotations provided, the description carries the full burden. It discloses that the tool never reads the chain, that the covenant enforces limits regardless, and that results depend on the passed grant (stale input gives wrong numbers). This is transparent about the tool's behavior and limitations, going beyond a simple 'reports' statement.

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 well-structured and front-loaded with the core output, then clarifies what it is not, and ends with a caveat. Each sentence serves a purpose, and the content is not redundant or verbose for the information it conveys.

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 has nested objects and many fields in its schema, but no output schema. The description lists the key outputs (budget left, epoch headroom, etc.) and gives enough context for an agent to understand the tool's role. It lacks details about the exact output format or error handling, but for a read-only query tool, this is sufficient.

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% (both parameters have descriptions), so the schema already explains the parameters. The description adds minimal parameter-specific detail beyond 'the grant you passed' and 'stale descriptor', which is useful context but does not significantly expand on the schema's meaning. Baseline 3 is appropriate.

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 the tool's purpose: it reports the agent's current spending power (budget left, epoch headroom, per-transaction cap, largest single payment). It uses a specific verb ('reports') and resource ('spending power'), and distinguishes itself from chain balance and wallet settings, which helps differentiate from siblings.

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?

The description explicitly says 'Use it before planning a purchase' and clarifies that it is NOT a chain balance, implying when not to use it. It also warns about stale descriptors giving confident wrong numbers, which guides agents to pass current grant data. However, it does not name alternative tools or provide a comprehensive when-to-use/when-not-to-use matrix.

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