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

Annotations only cover openWorldHint and destructiveHint, so the description carries real weight here: it discloses the escrow prerequisite, the current unavailability, and that a capability token is produced for later use with reveal. That is substantive context beyond the annotations, though it says nothing about permissions, idempotency, or whether grants can be revoked.

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 short sentences, front-loaded with purpose followed by the precondition and the return value. The parenthetical about hash-only stamps is slightly awkward but earns its place as a critical caveat.

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 usefully explains the return value (a capability token consumed by reveal) and the prerequisite. For a two-parameter tool it is nearly complete; only the revocation/expiry behavior of the granted capability is unaddressed.

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 (proofId, granteeId) are already documented in the schema. The description adds no format, validation, or sourcing detail beyond that, so the baseline 3 applies.

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 (grant), a specific resource (decrypt access to escrowed content), and a precise scope (a specific identity). It also names the value returned, which separates it cleanly from siblings like reveal and revoke_proof.

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 an explicit precondition — only proofs created with content escrow opted in — and warns the capability is not yet live ('stamps are hash-only today'), which is exactly the when-not guidance an agent needs. It stops short of naming an alternative for the hash-only case.

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