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

With no annotations, the description carries the full burden and does well: it discloses the tool is free, has no side effects, touches no relay, reads expiry from the grant itself, and consults only the patron's revocation watermark. It omits auth requirements and any rate/latency notes, keeping it below 5.

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?

Front-loads the core purpose in the first sentence, then adds only supporting context about the mental model and side effects. It is appropriately sized with no filler, though the multi-line backtick formatting is slightly noisy.

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 explained, and the description covers purpose, cost, side effects, and data sources. It is nearly complete for a free read-only check, with only auth/permission context missing.

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 description coverage is 100%, so both parameters (dpop_token, patron_npub) are already fully documented in the schema. The description adds no syntax or format detail beyond that, matching the baseline 3 when the schema does the heavy lifting.

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 ('Check whether a proof grant is still valid') and frames the purpose relative to the npub-proof flow and its goal. It clearly identifies the resource, though it does not differentiate against the actual sibling list (the many weather_check_* tools) since it only references the non-sibling 'check_oauth_status'.

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 a concrete when-to-use scenario: a calling agent asking 'will my next paid call accept this dpop_token?' before burning credits on a guaranteed failure. There are no explicit exclusions or named in-list alternatives, so it stops short of the 5 tier.

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