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

Annotations already declare read-only, idempotent, non-destructive behavior. The description adds meaningful context beyond them: only grant metadata is returned (never private keys, plaintext or EncDEK) and XGR RPC authorizes visibility based on the signed permit. It does not describe pagination behavior, but the added data-boundary and authorization context is substantive.

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, front-loaded with the core action, followed by data-boundary and authorization constraints. Every sentence adds value with no repetition.

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?

Output schema covers return values and parameter schema is fully documented. The description fills in the critical authorization and data-secrecy context. Minor gap: nothing about result cardinality or limit behavior, though the schema documents limit.

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%, so baseline is 3. The description clarifies that rid optionally filters results and that the permit governs authorization, but adds no syntax or format details beyond the schema, which itself uses generic placeholder descriptions.

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: lists grants visible to the permit signer, optionally filtered by RID. It does not explicitly name or differentiate from the sibling list_xgr_grants_for_readkey, so an agent must infer the distinction from the 'permit signer' scoping.

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?

Usage context is implied by 'visible to the permit signer' and the RID filter, but there is no explicit when-to-use guidance or comparison against list_xgr_grants_for_readkey. The agent is left to infer that this is the permit-scoped variant.

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