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

With no annotations, the description carries the burden and does well: it discloses the owner-auth requirement, the ownership scoping of results, and that private key material is never returned, while explicitly closing off export/decrypt capabilities. Gaps remain around pagination, ordering, and whether revoked keys are included, which matter for a list endpoint.

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 tight sentences, front-loaded with the operation and scope, followed by the auth requirement and the negative capability. No redundant restatement of the name or schema.

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?

For a 3-parameter read tool with no output schema, the description compensates by naming the returned fields and the auth requirement, so an agent knows what it gets back. It would be complete with a note on result volume/pagination or whether filtering by chain returns multiple records.

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% and each parameter is already documented (chain as 'Optional chain filter', agentId, access_token JWT), so the description adds no parameter-level meaning. Listing 'chain' among returned fields could even be momentarily confused with the chain filter parameter.

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 (list) plus resource (payload-key records) and even enumerates what each record contains (public key, mode, chain, export count). The explicit 'never the private key' clause separates it from any key-export operation, and no sibling tool covers payload keys.

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?

Establishes the precondition clearly ('for an agent you own', 'Requires access_token') and rules out a related path by noting that exporting/decrypting keys is not exposed over MCP. It stops short of an explicit when-to-use-vs-alternative statement, though no sibling tool competes for this job.

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